This field trip route highlights the main access roads and overlooks at Grand Canyon National Park’s North Rim (Figure 2.1 of FIELD GUIDE TO THE GEOLOGY OF THE NORTH RIM). The route initially follows AZ Hwy 67 into the park through Kaibab National Forest, but subdivides onto each of the park’s paved roads terminating at Bright Angel Point, Cape Royal, and Point Imperial. The road to Bright Angel Point offers access to all of the park’s visitor facilities, including the North Rim Visitor Center, Backcountry Office, North Rim Campground, Grand Canyon Lodge, and other facilities. This road also hosts the trailheads for the pleasant, family-friendly Transept and Uncle Jim Trails, the somewhat longer but rewarding Widforss Trail, and the awesome but strenuous North Kaibab Trail. If the Bright Angel Point Road takes you to the heart of the park, then the dual Fuller Canyon-Imperial Point and -Cape Royal Roads bare its soul on the Walhalla Plateau, offering wonderful drives through subalpine to montane coniferous forests, gorgeous scenic vistas and trail access to Cape Final, Cape Royal’s seldom visited, but uniquely spectacular twin. Point Imperial’s exceptional views and equally amazing geological revelations are afforded from a short spur road off the Fuller Canyon Road, a North Rim destination not to be missed. Roadside overlooks and hiking trail options on the North Rim combine to entertain, enthrall, and educate with an exemplar geologic story preserved in the canyon’s cliffs and slopes of varicolored rock layers and complex structural features. The classic Paleozoic sedimentary rock sequence, pervasively exposed from every vista, offers a spectacular opportunity to study sedimentation on a passive continental margin and adjoining coastal plain affected by marine invasions and retreats. Their later uplift and deformation by regional mountain building is revealed by the East Kaibab Monocline, best observed from Point Imperial and Cape Final. The tilted stack of sedimentary rocks forming the Grand Canyon Supergroup are well-displayed from Walhalla Plateau overlooks and the lower North Kaibab Trail, offering a record of the growth and sundering of a supercontinent, inundation and retreat of epicontinental seas, and tectonism and beveling by erosion. And although the crystalline basement rocks are more difficult to see, Bright Angel Point does offer a glimpse, and for the hardy, there is always a backpacking trip down the North Kaibab Trail if you feel the need to get up close and personal with the Grand Canyon’s oldest rocks.
To commit to a telling of this geological story, one can make as much effort as desired or permitted by the constraints of time and physical ability. The exceptional and endearing overlooks at Bright Angel Point, Cape Royal, and Point Imperial can provide enough scenic wonder and dispense with enough geologic detail to rough out the major elements, but day-hiking on the Cape Final, Uncle Jim, and/or Widforss Trails will flesh in some further attributes, and a backpacking excursion on the North Kaibab Trail from rim to river will add all of the nuances and finer details that make this story a true contender for top honors in natural history, commiserate with the excursions necessary to reach them of course.
Route Descriptions
Park Entrance Road (AZ Hwy 67)
0.0 (0.0) Refer to Map 2A.1. Intersection of U.S. Hwy 89A and AZ Hwy 67 (the entrance road to the North Rim of Grand Canyon National Park). This location also marks the beginning of Field Trip 2E, but for now, turn onto AZ Hwy 67 and head south to embark on Field Trip 2A. Almost immediately, a road to the right provides access to the Jacob Lake Inn, offering gasoline, great cookies, and souvenirs; and the Kaibab National Forest’s Kaibab Plateau Visitor Center with interpretive displays and staff available to answer questions about road conditions on the national forest.
0.4 (0.4) Intersection of AZ Hwy 67 and FS Rd 461. FS Rd 461 forms the end of Field Trip 2D; it ascends Warm Springs Canyon from FS Rd 22. Continue straight on AZ Hwy 67.
0.6 (0.2) The road cuts on the left-hand side of the road here expose weathered, buff-yellow Kaibab Limestone, note the resistant dull gray chert nodules common to the limestone. The Kaibab Plateau is capped by this resistant Paleozoic rock unit nearly everywhere. The road sticks to the ridge dividing the upper drainage of Orderville Canyon on the left, and Warm Springs Canyon on the right.
6.5 (5.9) FS Rd 205 on the left; just ahead, AZ Hwy 67 bends to the right as it ascends to the top of Big Ridge paralleling the axis of the East Kaibab Monocline.
7.7 (1.2) Refer to Map 2A.2. The road makes a right- then a left-hand bend as it enters a large area deforested by recent fires. Lack of forest cover reveals a surface of hills, swales, and occasional rounded depressions: this is classic karst terrain produced by dissolution of limestone. Normally found in moist environments where carbonate rocks are extensively exposed at the surface, the karst found here is no different; the higher elevations of the Kaibab Plateau receive ample precipitation to cause karstification. Incidentally, the warmer, dry conditions recently prevailing across the Colorado Plateau related to global warming may prevent reforestation of this area; karstification, being such a slow process typical of chemical weathering, will likely be unaffected over the long term.
14.0 (6.3) After making a wide 180º swing, AZ Hwy 67 reenters unburned forestland along a narrow grass floored valley. The valley is typically dry and may only see flowing water during peak spring snowmelt. As you drive, you might notice that the central part of the valley is lower than its ends, suggesting subterranean karst drainage as the only outlet.
16.2 (2.2) Your route passes a small fenced-in lake on the left named Crane Lake (Figure 2A.1); the shallower lake basin on the right just ahead is Grassy Lake (it often dries out by fall). Both lakes occupy distinctive rounded depressions; karst features called sinkholes.
Figure 2A.1. Crane Lake, a water-filled sinkhole formed by dissolution of the Kaibab Limestone.
18.4 (2.2) AZ Hwy 67 begins traversing a large meadowland called Pleasant Valley which appears to have a more distinctive drainage outlet to the east. Pleasant Valley has a rough N-S alignment and is fault-controlled, with displacement down to the west. The valley is floored by weathered sediments derived from the Toroweap Formation.
21.7 (3.3) Refer to Map 2A.3. The road reaches the southern end of Pleasant Valley’s grassy meadow and is now ascending toward a narrow ridge comprised of Kaibab Limestone that separates this valley from an even larger fault-controlled one to the south.
23.0 (1.3) Traversing an S-curve, you reach the crest of the divide. A sinkhole depression in the Kaibab Limestone on your left contains tiny VT Lake. Shortly, the road drops into the upper end of De Motte Park, an elongated grassy valley underlain by weathered Toroweap Formation (Figure 2A.2). The valley is aligned N-S along the De Motte Fault, another normal fault with displacement down to the west. A narrow, deep, trench-like valley runs parallel to De Motte Park, and is eroded along the trace of the Uncle Jim Fault, with similar displacement (better viewed on Map 2B.1). Both faults are oriented in tandem with the axis of the East Kaibab Monocline; it is likely that all of these structures formed in unison.
Figure 2A.2. De Motte Park, a long, narrow meadowland seemingly out of place on the forested Kaibab Plateau occupies a trench eroded through the Kaibab Limestone and into Toroweap Formation along the De Motte Fault.
25.6 (2.6) The entrance road to privately owned Kaibab Lodge lies on the right-hand side of the road. Lodge rooms, cabins, and campsites are available. The North Rim Country Store and Restaurant lies on the opposite side of the road.
26.5 (0.9) An important four-way road intersection occurs here; AZ Hwy 67 runs north-south, FS Rd 22 heads to the right, and FS Rd 611 heads to the left. This intersection is a busy one; it serves as the beginning of Field Trip 2B and 2D, and the ending for Field Trip 2C. Deer Lake, fenced in to keep out grazing cattle and buffalo, forms an almost perfectly circular lake occupying a sinkhole at the northwest quadrant of the intersection.
27.1 (0.6) Indian Lake on the left occupies another small sinkhole. Several more depressions formed on the valley floor can be seen near Indian Lake and just ahead on the right.
32.5 (5.4) Refer to Map 2A.4. Grand Canyon National Park boundary and entrance sign; just ahead is the entrance fee station which lies very close to the main drainage divide separating De Motte Park from the headwaters of The Basin and Outlet Canyon draining southward to the Colorado River.
33.4 (0.9) Shortly after exiting the entrance station, AZ Hwy 67 enters Upper Little Park, another smaller basin floored by weathered Toroweap Formation formed along the De Motte Fault. Upper Little Park is a tributary to The Basin and Outlet Canyon. Little Park Lake lies to the left of the road here, another water-filled sinkhole depression.
34.0 (0.6) The road first bends sharply to the left, then back to the right just ahead as is leaves Upper Little Park and enters a narrow tributary with similar alignment. This smaller canyon follows the trace of the Uncle Jim Fault which runs closely parallel to the De Motte Fault here.
35.9 (1.9) Descending through the narrow defile, the road reaches this low point where the tributary veers sharply west to rejoin its parallel companion draining down from Upper Little Park. Map 2A.4 clearly shows the two tributary valleys formed side-by-side. From here, the road quickly climbs to the crest of a drainage divide, then plunges into another narrow canyon controlled by the same Uncle Jim Fault; although this next valley drains southeast and east and is a tributary of Thompson Canyon. The De Motte Fault and the Uncle Jim Fault diverge at this point.
39.3 (3.4) AZ Hwy 67 makes a wide 180º turn and the small tributary canyon you were following joins the main Thompson Canyon coming in from the left. Here, Thompson Canyon and the road veer onto a southerly course following a sinuous path cut along the trace of the Uncle Jim Fault. A notable change in rock type begins to occur in road cuts within Thompson Canyon which exposes the Toroweap Formation in its lower walls. The rocks appear in brown and reddish hues and become a mix of mudstones, sandstones, and limestones.
40.1 (0.8) The Uncle Jim Fault diverges from Thompson Canyon here, heading southeast, as the road continues south along the bottom of Thompson Canyon. Notice that the area was severely burned recently. A dense growth of brush and quaking aspen have grown up in place of the coniferous forest and it may be that the ponderosa pines that once grew here will not regenerate if climate changes too dramatically in the coming decades.
42.4 (2.3) Refer to Map 2A.5. Intersection of AZ Hwy 67 and the Fuller Canyon Road (on the left). The Fuller Canyon Road will take you to Point Imperial and Cape Royal (described later as separate, supplemental auto-touring routes to the main route of Field Trip 2A).
42.6 (0.2) Intersection of AZ Hwy 67 and the Point Sublime Road (on the right). A turn onto the Point Sublime Road takes you about six tenths of a mile to a parking area and trailhead on the left for the Widforss Trail (see the Widforss Trail – Tr 2A.5 described in the Optional Hiking Trails section of Field Trip 2A); but continuing straight on the gravel road begins Field Trip 2C.
43.2 (0.6) The entrance to the trailhead parking area for the North Kaibab Trail and Uncle Jim Trail lies to the left-hand side of the road (see the North Kaibab Trail – Tr 2A.2 and Uncle Jim Trail – Tr 2A.4 described in the Optional Hiking Trails section of Field Trip 2A). The small valley here occurs along the NW-SE oriented trace of the Roaring Springs Fault. The fault continues into the large canyon to the southeast where it merges with the NE-SW oriented Bright Angel Fault. Roaring Springs, source of all water consumed on both rims of the Grand Canyon, issues from the fault fractured rocks near the point of merger.
44.0 (0.8) The road on the right takes you to the North Rim’s Backcountry Office where you can obtain up-to-date information on trailhead roads and trail conditions, as well as permits for overnight stays below the rim and in other designated backcountry areas.
44.2 (0.2) The entrance road for North Rim Campground lies on the right-hand side of the road here.
45.2 (1.0) The end of AZ Hwy 67 at the parking area for the North Rim Visitor Center and and Grand Canyon Lodge. Find a parking spot (be patient, it can be quite crowded), and take in the visitor’s center. Afterwards, the short hike to Bright Angel Point is a must.
If you have a few hours, or even a few days, I suggest making the effort to hike the Transept Trail; and if you are looking for more phenomenal views and a great family-friendly hike for all ages, I suggest a trek to Bright Angel Point that includes the longer Transept Trail for a wonderful first exposure to North Rim hiking (see the Transept Trail – Tr 2A.3 described in the Optional Hiking Trails section of Field Trip 2A). For this latter option, I suggest driving to the Bright Angel Point parking area and beginning on the trail to the left (east) side of the visitor’s center as you face toward the point: hike out to Bright Angel Point, then get on The Transept Trail, this time on the left (west) side of the lodge as you face toward the parking area, and hike back to the North Rim Campground. You will then need to walk from the campground back to the parking area to pick up the car, but a shortcut via the Bridle Trail can be taken.
A walk to Bright Angel Point should begin at the east or southeast edge of the North Rim Visitor Center parking area. The trail sticks close to the rim, and to the left of the Grand Canyon Lodge cabins, and offers good views into the upper end of Bright Angel Canyon (Figure 2A.3). Much of the Paleozoic sedimentary rock sequence is exposed in the canyon’s walls, and without too much difficulty, any visitor to the Grand Canyon can quickly learn to identify the rock layers based on their colors and patterns of differential erosion (Figure 2.5 of FIELD GUIDE TO THE GEOLOGY OF THE NORTH RIM). In the photograph, the whitish-colored cliff band that occurs just below the rim is the Permian Coconino Sandstone, above that unit are two other Permian formations, the slope-forming Toroweap Formation, overlain by the Kaibab Limestone (not forming a very distinctive cliff here as it usually does). Below the Coconino is a thick layer of reddish slopes and ledgy rock units; the Permian Hermit Formation, followed by the Supai Group. The Esplanade Sandstone forms the first thick cliff-band, and three, hard to distinguish, Pennsylvanian rock units below, round out the Supai Group. Below the Supai, the Mississippi Redwall Limestone usually appears as a distinctive, massive, reddish-colored cliff, but here the cliff is blockier, broken up by numerous gullies; the thick unit may be heavily fractured by the Bright Angel and Roaring Springs Faults along which the canyons have cut their courses. The thick slope-forming layers below the Redwall are the Cambrian Muav Limestone and Bright Angel Shale; the Tapeats Sandstone is not exposed in this view.
Figure 2A.3. Upper Bright Angel Canyon from the trail to Bright Angel Point east of Grand Canyon Lodge; differential erosion of resistant and weaker rock units can be used to identify the Paleozoic sedimentary rocks exposed in its walls.
Continue your hike to Bright Angel Point, at just under half of a mile, it’s an easy jaunt. From here, the entire Paleozoic sequence is exposed and more easily identified (Figure 2.5 and Figure 2.6 of FIELD GUIDE TO THE GEOLOGY OF THE NORTH RIM); take some time to determine if you can unravel it. Deep in Bright Angel Canyon, a distinctive, brownish-colored cliff band stands out; this is the Tapeats Sandstone. Higher in the canyon, the Tapeats rests on sedimentary rocks of the Grand Canyon Supergroup tilted to the northeast; the Bright Angel Fault forms a bounding normal fault on the east side of a large one-sided graben that preserves the Supergroup here (Figure 2.7 of FIELD GUIDE TO THE GEOLOGY OF THE NORTH RIM). Descending lower in the canyon, the crystalline basement rocks have been unearthed below the base of the graben. The Great Unconformity forms the erosional gap between the basal Paleozoic Tapeats Sandstone and the Proterozoic Grand Canyon Supergroup and crystalline basement rocks. The unconformity ages down canyon because the rocks below the Tapeats change from Late to Middle Proterozoic, while the nature of the unconformity changes too. Angular unconformities separate flat-lying sedimentary rocks from tilted (deformed) ones, while nonconformities separate sedimentary rock from crystalline basement.
As you return toward the visitor center and lodge, good views of The Transept’s deep, narrow canyon are available on the left-hand (west) side of the trail (Figure 2A.4). Across the depths of The Transept to the west lies Oza Butte and Widforss Point capped by Kaibab Limestone (Figure 2A.5). The cliff-slope stair steps caused by differential erosion make the sequence of Paleozoic sedimentary rocks easy to distinguish in this canyon because they are not fault-shattered as in upper Bright Angel Canyon. When you approach the lodge cabins, a well-marked sign indicates that if you bear left near the overlook just below the lodge’s west patio, your trail merges with the Transept Trail. Veer to the right here to return to the Visitor Center parking area.
Figure 2A.4. The Transept forms a deeply recessed canyon on the west side of the promontory on which the North Rim visitor facilities sit.
Figure 2A.5. Oza Butte (to the left) and Widforss Point (beyond the saddle in the ridge connecting to Oza Point), both lying on the west side of The Transept, present one of many eye-catching moments along The Transept Trail.
Fuller Canyon-Point Imperial Road
0.0 (0.0) Refer to Map 2A.5. This route description assumes you are staying at the North Rim Campground or Grand Canyon Lodge. Return to the intersection of AZ Hwy 67 and the Fuller Canyon Road at mile 42.4; then turn right onto the Fuller Canyon Rd toward Point Imperial and Cape Royal.
1.4 (1.4) Here, Fuller Canyon Rd intersects diagonally with two short drainages that are oriented northwest-southeast. These valleys are eroded along the trace of the Uncle Jim Fault. Just ahead, the road traverses a lengthy section of burned over forest, now recovering with brush and groves of aspen.
3.1 (1.7) The road makes a sharp right turn here as it climbs to a flat drainage divide between Fuller Canyon and the headwaters of Bright Angel Canyon. Both tributaries (the Fuller Canyon one you ascend, and the Bright Angel one you soon descend, are cut along a northwest-southeast oriented fault splay of the Bright Angel Fault. Notice that the divide area is devoid of conifers; the area was recently subjected to a large forest fire and is now growing back thick with quaking aspen.
5.4 (2.3) Refer to Map 2A.4. Intersection of Fuller Canyon Road, with the Point Imperial Road to the left, and the Cape Royal Road to the right. Here, the headwaters of Bright Angel Canyon have dissected through the Kaibab Limestone to expose the Toroweap Formation’s brown and reddish layers of predominantly mudstones. Turn left onto the Point Imperial Road, it’s a relatively short drive of about five miles round-trip to one of the choicest overlooks in the park.
8.1 (1.7) Refer to Map 2A.6. The road makes a right-hand, counterclockwise loop into the Point Imperial parking area. Stop here and take a short walk to enjoy the views while you contemplate the amazing geology on display!
The overlook at Point Imperial is especially fantastic at sunrise and sunset, but observation of the geology is good almost any time of day. From this scenic vista, one gets an excellent bird’s eye view of the East Kaibab Monocline and the Butte Fault which produced the gargantuan fold. Your view looking south is nearly in alignment with the fold axis and its paired fault; while looking east, you can readily observe Marble Canyon and the Marble Platform beyond where displacement of the rock layers downward across the fold (relative to your position at the overlook) is easily observed.
Some review of the geology we are about to discuss is in order. Recall that the Butte Fault was first formed about 740 million years ago during rifting of the Rodinian supercontinent. At this time the Grand Canyon region lay to the east of the main rift zone, but continental crust in the area was stretched generally east-west and fractured along extensive NW-SE oriented normal faults such as the Butte Fault (Figure 2.10 and Figure 2.11 of FIELD GUIDE TO THE GEOLOGY OF THE NORTH RIM). However, as regional extensional faulting progressed, deposition of the uppermost Late Proterozoic Grand Canyon Supergroup rocks continued, and the upper Chuar Group and Sixtymile Formation were gradually folded into the Chuar Syncline. Normal faulting offset crustal blocks forming a series of parallel basins; one-sided grabens that preserved northeasterly tilted Supergroup rocks from subsequent erosion. These wedge-shaped remnants of Supergroup rocks are mainly observed in isolated pockets along the main Colorado River corridor and some of its major tributaries (Figure 2.7 of FIELD GUIDE TO THE GEOLOGY OF THE NORTH RIM). Down-to-the-east displacement on the Butte Fault was the most significant, which formed an immense graben that preserved the entire package of sedimentary rocks comprising the Grand Canyon Supergroup (Figure 2.10 and Figure 2.11 of FIELD GUIDE TO THE GEOLOGY OF THE NORTH RIM); the only graben exposed in the Grand Canyon that reveals the Nankoweap Formation, the Chuar Group, and the Sixtymile Formation, comprising the upper half of the Late Proterozoic sequence.
A subsequent stage of activity on the Butte Fault occurred much later in the Late Cretaceous and Early Tertiary during the Laramide Orogeny. A compressional tectonic regime associated with shallow subduction of the Farallon Plate beneath North America from 80-40 million years ago rumpled the crust of the western North American craton. Reactivated as reverse faults, movement on ancient basement faults formed large monoclinal folds in the Paleozoic and Mesozoic sedimentary cover of the Colorado Plateau. In the Grand Canyon region, compressional movement on the Butte Fault produced the East Kaibab Monocline and associated Kaibab Upwarp (Figure 2.2 and Figure 2.3 of FIELD GUIDE TO THE GEOLOGY OF THE NORTH RIM).
Walk to the end of the path leading from the parking area first. To gather your bearings, look directly ahead of you to Mount Hayden, a pinnacle of buff-colored Coconino Sandstone perched precariously on red mudstones of the Hermit Formation (Figure 2A.6). On the skyline to the left of Mount Hayden you can see the Marble Platform and Cliffs of the Palisades, the notch in the cliff face just left of center is the canyon of the Little Colorado River at its confluence with the Colorado. Geologically, the most obvious thing you notice is the offset between the Marble Platform on the left and the Kaibab Plateau where you stand. Both features are capped by the Kaibab Limestone, and the offset is real, a product of monoclinal folding over the Laramide Orogeny-reactivated Butte Fault. There is additional evidence of the Butte Fault and East Kaibab Monocline at a finer scale, so we need a closer look. Focus your attention on the Little Colorado River’s canyon.
Figure 2A.6. A view southward from Point Imperial; Mount Hayden and Nankoweap Canyon occupy the foreground, while the Marble Platform and Cliffs of the Palisades (notched by the canyon of the Little Colorado River at its confluence with the Colorado River) lies on the skyline.
Figure 2A.7 shows a closer, early evening view of the Little Colorado-Colorado River confluence; the mesa directly in front of the shadowy Little Colorado River canyon is Chuar Butte, capped by Kaibab Limestone, just as the Cliffs of the Palisades behind it. Notice the long, gray-colored ridge running diagonally from left (northeast) to right (southwest) in front of Chuar Butte; this is the Redwall Limestone exhibiting its dull gray color, typical of limestones. However, what is so unusual about the unit exposed here is that you are seeing it tilted on edge by reverse (compressional) movement on the Butte Fault which lies just to the fore. The Muav Limestone, Bright Angel Shale, and Tapeats Sandstone were squeezed and sheared into nonexistence against the fault as it moved. The darker gray, slope-forming rock juxtaposed against the Redwall ridge is mudrock of the Galeros Formation, part of the Chuar Group of the Late Proterozoic Grand Canyon Supergroup. Now look to the far right of the photograph and you can be the Redwall Limestone lying flat, exposed in the upper walls of Nankoweap Canyon draining the east side of the Kaibab Plateau below you. There, it is underlain by the Muav Limestone, Bright Angel Shale, and Tapeats Sandstone just as expected.
Figure 2A.7. A closer view of the Butte Fault where it lies at the foot of Chuar Butte; here, the Redwall Limestone forms a nearly vertical ridge where it is upturned against the fault during Laramide compression.
What is probably not immediately obvious is the evidence of the Butte Fault’s initial development in the Late Proterozoic and its association with synclinally folded Grand Canyon Supergroup rocks; for that, we need a particularly discerning look. Move your focus to the left, upcanyon to the northeast, until you see a large narrow mesa isolated from the Marble Platform, but comprised of similarly flat-lying Paleozoic sedimentary rock layers (Figure 2A.8). The table-like feature is Nankoweap Mesa, once again capped by Kaibab Limestone; lower on its flanks, you can see the red, ledgy rocks of the Supai Group. Immediately to the fore, the Redwall Limestone is tilted into a similar gray ridgeline as we saw earlier to the fore of Chuar Butte. Here, the reason is the same, Laramide displacement on the Butte Fault has tightly folded the Redwall, while squeezing and thinning the Cambrian sedimentary rocks below it. But this folding, while quite interesting, is not the folding we have come to observe. Directly in front of the Redwall is a red-gray pile slope-forming rock units folded into an arcuate ridge resembling the bow on a ship, these are the mudstones and sandstones of the Kwagunt Formation and the folding is direct evidence of the Chuar Syncline. The small pyramid-shaped hill encircled by the Kwagunt ridge is Nankoweap Butte, capped by an isolated outcrop of Sixtymile Formation, uppermost unit of the Grand Canyon Supergroup. The flanks of Nankoweap Butte are comprised predominantly of mudstones, also part of the Kwagunt Formation. Folding of these units to form the Chuar Syncline is used by geologists as evidence that extensional movement on the Butte Fault continued even as these units accumulated.
Figure 2A.8. The Chuar Syncline, a Late Proterozoic fold structure formed during extensional, normal fault movement on the Butte Fault associated with rifting of the supercontinent Rodinia to the west of the Grand Canyon region.
As you make your why back to the parking area, be sure to take in the expansive scenery to the east and northeast. On a clear day, Point Imperial offers a superb view of Saddle Mountain and the northern tributary of Nankoweap Canyon, the Marble Platform and Marble Canyon, as well as more distant the Vermillion Cliffs and Echo Cliffs beyond (Figure 2A.9). Figure 2A.10 brings this perspective into sharper focus will a closer sunset view aligned with the notch in the ridge just to the fore of Saddle Mountain. Once again, it is without difficulty that one can observe the offset between the Kaibab Limestone-capped Marble Platform and your similarly composed location atop the Kaibab Plateau, courtesy of the East Kaibab Monocline and associated Butte Fault. But bring your gaze in closer, on the left (northeast) lies Saddle Mountain, capped by isolated remnants of Kaibab Limestone; here you can clearly see layers of resistant cliff-forming and weak slope-forming sedimentary rock titled eastward over the fold axis. Here, you literally stand on the apex of the monocline and upwarp, comprised of steeply tilted rock layers to the east, and very gradually tilted layers to the west. Now direct your gaze outward to the Vermillion Cliffs and Echo Cliffs on the skyline. The rocks there are of Mesozoic age (Figure 2.2 of FIELD GUIDE TO THE GEOLOGY OF THE NORTH RIM), comprised of the mudrocks of the Triassic Moenkopi and Chinle Formations capped by the resistant sandstones of the Jurassic Wingate, Moenave, Kayenta, and Navajo Formations. Pervasive erosional stripping during the moist climate of the Tertiary Great Denudation removed the Mesozoic rocks from the Kaibab Upwarp and Marble Platform. Later erosion under a warmer, drier climate confined erosion to canyon cutting, which we see in the form of Marble Canyon and the Grand Canyon today.
Figure 2A.9. The eastward view from Point Imperial; eastward tilted Saddle Mountain, capped by isolated blocks of Kaibab Limestone, and the north fork of Nankoweap Canyon lie on the left, with the Marble Platform visible in the distance on the right.
Figure 2A.10. A closer view to the northeast from Point Imperial, beyond Saddle Mountain, reveals the wide, nearly level expanse of the Marble Platform dissected by the Colorado River’s Marble Canyon; beyond lie the Vermillion Cliffs and Echo Cliffs, comprised of lower Mesozoic rock units not yet stripped from the region by erosion.
Fuller Canyon-Cape Royal Road
0.0 (0.0) Refer to Map 2A.5. This route description assumes you are staying at the North Rim Campground or Grand Canyon Lodge. Return to the intersection of AZ Hwy 67 and the Fuller Canyon Road at mile 42.4; then turn right onto the Fuller Canyon Rd toward Point Imperial and Cape Royal.
1.4 (1.4) Here, Fuller Canyon Rd intersects diagonally with two short drainages that are oriented northwest-southeast. These valleys are eroded along the trace of the Uncle Jim Fault. Just ahead, the road traverses a lengthy section of burned over forest, now recovering with brush and groves of aspen.
3.1 (1.7) The road makes a sharp right turn here as it climbs to a flat drainage divide between Fuller Canyon and the headwaters of Bright Angel Canyon. Both tributaries (the Fuller Canyon one you ascend, and the Bright Angel one you soon descend, are cut along a northwest-southeast oriented fault splay of the Bright Angel Fault. Notice that the divide area is devoid of conifers; the area was recently subjected to a large forest fire and is now growing back thick with quaking aspen.
5.4 (2.3) Refer to Map 2A.4. Intersection of Fuller Canyon Road, with the Point Imperial Road to the left, and the Cape Royal Road to the right. Here, the headwaters of Bright Angel Canyon have dissected through the Kaibab Limestone to expose the Toroweap Formation’s brown and reddish layers of predominantly mudstones. For now, turn right onto the Cape Royal Road for a grand tour of the Walhalla Plateau and its many scenic and geologically significant vistas.
6.5 (0.9) Refer to Map 2A.6. The Cape Royal Road climbs rapidly from Bright Angel Creek to a hairpin turn and a small parking area where the Ken Patrick Trail crosses the road. A good view straight down the main fork of Nankoweap Canyon is worth a brief visit here (Figure 2A.11).
Figure 2A.11. The main branch of Nankoweap Canyon as viewed from the Ken Patrick Trail crossing on the Cape Royal Road; the overlook offers another opportunity to see Nankoweap Butte, Nankoweap Mesa, and the Butte Fault.
To get you properly oriented, look due east, Alsap Butte is the flat-topped pyramid on the ridge forming the canyon’s opposite wall; now, if you follow that ridge to the left (northeast), the similarly flat-topped butte tucked down in the drainage is Nankoweap Butte. As discussed at the Point Imperial stop, Nankoweap Butte is comprised of the youngest Grand Canyon Supergroup rocks, roughly 740 million years old, folded into a gentle syncline. Behind Nankoweap Butte is the elongate Nankoweap Mesa, and in between them lies the Butte Fault. Late Proterozoic crustal extension initially formed the Butte Fault as a normal fault bounding the eastern side of a huge graben that now preserves Supergroup rocks. Deposition of the youngest rock units of the Supergroup coincided with fault motion causing their synclinal folding.
At this location, you are poised on the neck of the Walhalla Plateau, a narrow connection of rock capped by Kaibab Limestone that divides the watershed of Nankoweap Creek from Bright Angel Creek. Headward erosion of both drainages will eventually turn the Walhalla Plateau into an isolated mesa, similar to Powell Plateau and many others in the Grand Canyon region.
10.0 (3.5) Refer to Map 2A.7. Leaving the Ken Patrick Trail parking area, your route begins a dozen tight turns as it weaves in and out of small washes draining west into Bright Angel Creek, eventually bringing you to Vista Encantada. Pull into the parking area to enjoy more spectacular views into the southern fork of Nankoweap Canyon (Figure 2A.12).
Figure 2A.12. Vista Encantada offers a marvelous view into the southern fork of Nankoweap Canyon; consider that the Kaibab Limestone forming the foundation of your perch is one and the same with the rock layer capping the Marble Platform opposite the river gorge in the distance, a substantial difference in elevation made possible by uplift of the Kaibab Platform during the Laramide Orogeny 80-40 million years ago.
As your gaze wanders over the scenery, consider your location, among pine and fir requiring substantially cooler and moister conditions than those that prevail far across the canyon and several thousand feet lower on the Marble Platform, and yet, you stand on the Kaibab Limestone, the same rock that caps the platform. This feat of geologically engineering is brought to you by compression and reverse faulting on the Butte Fault during the Late Cretaceous to Early Tertiary Laramide Orogeny resulting in the Kaibab Upwarp on which you now stand.
11.5 (1.5) An unofficial gravel pull-out on the left-hand side of the road here provides an excellent vantage point to view the East Kaibab Monocline and upper Nankoweap Canyon to the northeast.
11.7 (0.2) The pull-out for Roosevelt Point lies on the left-hand side of the road. Turn in here and walk the short 0.3-mile lasso-shaped trail to and from the overlook. A recent fire has burned over the area making for clear views, but with a new climate regime induced by human activity, one wonders if the ponderosa forest will regenerate.
On the left (north) side of the overlook lies the south fork of Nankoweap Canyon and great views to the northeast (Figure 2A.13). Careful observation should reveal a down-to-the-east bending of the Paleozoic rock layers from the plateau rim, best viewed in the north wall of Nankoweap Canyon below Saddle Mountain. This of course is related to the East Kaibab Monocline whose axis runs nearly parallel to the plateau’s rim. On the right-hand side of the overlook, you are afforded a one-time opportunity to view the depths of Kwagunt Canyon (Figure 2A.14). Train your eyes on the bed of the creek and follow it down canyon, the small blocky tower of stone at the distant end of the valley is Kwagunt Butte. Just to the fore of the butte lies a gray ridge of upturned Redwall Limestone lying juxtaposed against the Butte Fault. Exposed in the ridge in front of the Redwall is the buff-colored, cliff-band of the Tapeats Sandstone on the west side of the fault. Below the flat lying Tapeats, layers of rock are tilted down to the east, these are layers of Kwagunt and Galeros Formation, part of the Late Proterozoic Grand Canyon Supergroup, deformed by graben formation during the breakup of the Rodinian supercontinent about 740 million years ago.
Figure 2A.13. Roosevelt Point offers excellent views; the one portrayed here is northward, into the south fork of Nankoweap Canyon and back along the length of the plateau rim to Saddle Mountain, another great opportunity to see evidence of the East Kaibab Monocline in the folded rocks of the upper Paleozoic sequence.
Figure 2A.14. An eastward view from Roosevelt Point down the axis of Kwagunt Canyon, across Marble Canyon, and to the Marble Platform beyond; the upturned gray Redwall Limestone offering evidence of the Butte Fault, and tilted reddish layers of ancient Grand Canyon Supergroup rocks below the Tapeats Sandstone, lay to the right of Kwagunt Creek and to the fore of Marble Canyon.
13.7 (2.0) The road reenters dense ponderosa pine forest at roughly this location and remains in healthy, unburned forest the remaining distance to Cape Royal; quite a gorgeous drive!
17.1 (3.4) The parking lot for the Cape Final Trailhead lies on the left-hand side of the road. If time permits, this short hike of about three and a half miles is well worth it (see the Cape Final Trail – Tr 2A.1 described in the Optional Hiking Trails section of Field Trip 2A). The views from Cape Final are quiet, uncrowded, and quite spectacular; and the walk through the ponderosa pine forest is pleasantly soothing. Should you desire a lingering visit, you can even apply for an overnight backcountry permit to camp at the point, for its scenery, solitude, and geologic spender, one of the finest overnight stays in the park.
18.1 (1.0) The north entrance to the Walhalla Overlook parking area is on the left; pull in here. If you didn’t hike to Cape Final, then this scenic vista will dazzle you with its view straight down the Unkar Creek drainage (Figure 2A.15).
On a clear day, you can readily make out the Unkar Delta and red sandstone cliffs of the Dox Formation at the stream’s confluence with the Colorado River. Here the river’s corridor is unusually wide, a product of its erosion through the relatively weak sedimentary rocks of the Grand Canyon Supergroup. Streams are better able to migrate laterally when eroding through weaker rocks (but are forced to use their energy to cut downward when rock strength is high – hence the narrower Granite Gorge further down canyon where the Colorado cuts through crystalline basement rocks). In the distance, the slight curvature of the Coconino Plateau’s upwarp (a southerly extension of the Kaibab Plateau isolated by erosion of the Grand Canyon) and the volcanic summits of the San Francisco Peaks perched on the tablelands to the south are easy to make out.
Figure 2A.15. Gorgeous Unkar Creek Canyon from the Walhalla Overlook, contemplate the geology and enjoy the view.
If you walk to the left (northeast) a bit, you can get a better view of the lower end of Unkar Canyon. Unkar Creek has built a large delta at its mouth where it joins the Colorado River (Figure 2A.16), an indicator of the age of this drainage, but also an indicator of powerful flash floods carrying heavy loads of coarse debris to the stream’s terminus. Take a closer look on the far side of the Colorado River, you can see the bend in the river channel and the cliff of red sandstones; growth of the delta has ongoing for a very long time and has continually pushed the river against the far wall, eroding a cliff. Notice that the red rock layers near the river are tilted downward to the east (Figure 2A.16), these are part of the thick package of sediments called the Dox Formation, part of a thicker sequence of rocks known as the Unkar Group, which is part of a massive pile of sedimentary rocks known as the Grand Canyon Supergroup, all deposited in the Late Proterozoic. Geologists attempt to define and map sediments with similar characteristics into “Formations”, formations with related characteristics of depositional histories may be categorized as “Groups”, and groups of related rocks can be lumped together into “Supergroups”. Now shift your gaze over to the left and upwards; the black rocks exposed in the cliff face are part of the Cardenas Basalt, the final formation to accumulate in the Unkar Group about 1100 million years ago. Careful examination of the rock outcrops in the area shows a thinner, gray unit above the Cardenas Basalt, these layers are the Nankoweap Formation deposited about 900 million years ago (the Nankoweap is well exposed in Nankoweap Canyon, hence its name – geologists often name rock units after geographic locations where they are found in abundance).
Figure 2A.16. Unkar Canyon from Walhalla Viewpoint affords a great view of the sedimentary rocks exposed along the Colorado River and cliffs of the South Rim.
You probably have already noticed that the sedimentary rocks above these Supergroup layers are more or less flat lying, these varicolored bands comprise the Paleozoic sequence of sedimentary rock so well recognized throughout the Grand Canyon (Figure 2.5 of FIELD GUIDE TO THE GEOLOGY OF THE NORTH RIM). They begin with the Middle Cambrian Tapeats Sandstone, deposited on the Great Unconformity (Figure 2A.16), an erosional gap in the rock record formed when the region was uplifted and peneplained following deposition of the Supergroup rocks (an erosional period of about 200 million years). While I indicated that the layers are generally undeformed, a close examination of the cliff exposures shows a slight bending downward to the east and west away from Tanner Canyon. Why? Tanner Canyon developed along the extension of the Butte Fault south of the Colorado River, the fault whose reverse movement during Late Cretaceous-Early Tertiary Laramide mountain-building generated the East Kaibab Monocline. Yes, the fold is more subtle on the South Rim, but still visible to those with a discerning eye.
Before you leave the parking area, note the sign across the road to your right (as you head toward Cape Royal) marking the location of the Cliff Springs Trail. This trail offers a brief two-mile, out and back stroll just below the plateau rim, a well-preserved Ancestral Puebloan granary, a hidden perennially dripping spring, and interesting geology. Once on the trail, you immediately descend along a cool, shady draw through a beautiful ponderosa pine woodland. Shortly, the path reaches a pile of large Kaibab Limestone boulders, a boulder perched atop the others creates a large void in which Ancestral Puebloans built a granary (a stone enclosure for storing grain – corn or wild seeds collected from nearby meadows on the upland) (Figure 2A.17).
Figure 2A.17. An Ancestral Puebloan granary in the Cliff Springs draw.
Your route soon enters a narrow defile cut into Kaibab Limestone. In just over a quarter of a mile, the trail passes onto a ledge overhung by crossbedded sandstones, thus indicating that you have descended below the Kaibab Limestone and are within the Toroweap Formation. From here to trails end, weaker thinly bedded mudstones and sandstones are undercut by weathering to form the ledge on which you walk. A variety of seeps and springs ooze water from the undercut layer (Figure 2A.18), some seeps are coated in odd moss-like growths covered in salt crystals. Water bleeding from tiny openings in the rock quickly evaporates in the warm dry air to leave the strange salt deposits behind. Near 0.6 miles into your stroll, several small pools of water have collected along the walkway, feed by dripping from above. Groundwater, emerging from openings along the contact between impermeable mudrocks and overlying porous sandstones, provides water for groundwater sapping, a combination of physical and chemical weathering processes that have preferentially undercut the sandstones and created the bench. The volume of water does not seem to be significant enough to supply the needs of more than a few individuals, so it is doubtful that granary building Ancestral Puebloans were using this source of water to supply a village or water crops; however, climate change may have reduced the rate of flow in recent years to the mere trickle we see today. The trail continues for a total length of about one mile, but becomes rather dubious after that. On your return route, note the far wall of the draw, the sharp contact between the Kaibab Limestone and Toroweap Formation in easy to pick out, while weathering-induced undercutting of weak mudrocks within the upper Toroweap that forms the bench on which you walk is nicely displayed (Figure 2A.19).
Figure 2A.18. Small springs and seeps produce a trickle of water from the contact zone between mudrocks and overlying sandstones in the Toroweap Formation.
Figure 2A.19. The narrow defile of Cliff Springs Canyon; here, undercutting of weaker mudrocks within the Toroweap Formation by groundwater sapping has formed a distinctive overhang and bench with the contact between the overlying Kaibab Limestone and Toroweap Formation readily observed in the background.
Return to the Walhalla Viewpoint parking area and your vehicle at your leisure. I hope you have enjoyed this little tour of rim edge environments.
19.0 Refer to Map 2A.8. Here, a small parking area on the left provides access to the Angel’s Window viewpoint, a short, but interesting stop. Angel’s Window is an arch eroded from a fin of Kaibab Limestone jutting from the cliff face above Unkar Canyon near Cape Royal (Figure 2A.17). Note the other smaller windows in the cliff closer to your position.
Figure 2A.20. Angel’s Window, a rare Grand Canyon arch formed in the Kaibab Limestone.
19.5 (0.5) The end of the Cape Royal Road and the parking area for the Cape Royal overlooks. Find a place to park (it is often crowded), and make the short walk of just over one mile round-trip to these world-class scenic vistas.
In about two-tenths of a mile, the trail brings you to a much closer view of Angel’s Window (Figure 2A.21). Here, it is worth a brief consideration of arch formation. Arches are rare in the Grand Canyon. It requires well jointed rock (in the Grand Canyon, thick, massive limestone such as the Kaibab Limestone and Redwall Limestone are generally well jointed); the joints are vertical fractures that form in response to differential stresses placed on a body of rock by the weight of overlying material and from tectonic pressures such as those created when the Kaibab Limestone in this area was uplifted by movement on the Butte Fault. Unloading and removal of burial pressure from erosion of overlying layers opens the joints to provide avenues for water’s egress, the chief agent in arch formation. You may also note that the limestone is distinctly bedded, and bedding planes can allow water to move laterally through rock more readily. The water is subject to freeze-thaw, especially high on the Kaibab Plateau, which causes frost wedging to pry apart inherent weaknesses in the rock, the aforementioned joints and bedding planes. Water also dissolves the limestone and carries away the broken bits and the ions in solution. Gradually, fractures are enlarged vertically downward to form the rock fin, then the processes of weathering and erosion can work laterally into the fin, conveniently along bedding contacts, eventually opening a hole within the fin, and voilà, an arch has formed.
Figure 2A.21. Angel’s Window, an arch formed in the Kaibab Limestone cliffs above Unkar Canyon, developed under a unique set of circumstances; a naturally cool and moist climate providing ample water and freeze-thaw processes and natural weaknesses in the rock, such as joints and bedding planes that allow water easy access into the rock.
The trail quickly brings you to a “Y” intersection; take the fork to the left first to complete your tour of Angel’s Window. Here, you won’t see the window itself, instead, the trail takes you out onto the tip of the rock fin in which the arch has formed. As you head out onto the arch, take note of the small wrinkles abundantly displayed on the flat surfaces on which you walk. These are ripple marks formed on bedding planes in the Kaibab Limestone (Figure 2A.22). Symmetrical ripples like these are indicative of wave action, probably formed by foul-weather conditions long ago on the tropical marine shelf environment where the lime muds accumulated. The overlook a the end of the arch provides great views into Unkar Canyon (Figure 2A.23). An expansive southeasterly view here offers up another exceptional vista of Unkar Creek Canyon. Freya Castle looms large in the foreground above and to the right of the canyon, while Vishnu Temple lies further to the right in the middle distance; both spires are capped by Coconino Sandstone. Taking in the Desert View skyline, you may notice that the Colorado River corridor wraps abruptly south, southwest, and then west around the Walhalla Plateau, butting up sharply against the Cliffs of the Palisades and the Coconino Plateau’s South Rim cliffs. Some geologists believe that the ancestral Colorado may have become entrapped by erosion into weaker, southeasterly tilted sedimentary rocks as it attempted to swing around the southern edge of the Kaibab Plateau, thus explaining the exceptionally steep cliffs lacking significant tributaries in the Desert View area.
Figure 2A.22. Symmetric ripple marks adorn bedding planes in the Kaibab Limestone fin of Angel’s Window indicating storm wave oscillation on an ancient tropical marine continental shelf (a quarter for scale).
Figure 2A.23. Unkar Canyon, Freya Castle, and Vishnu Temple from the Angel’s Window overlook.
Now return to the “Y” junction and head left down the right-hand fork to Cape Royal herself. This overlook is one of the finest to be had in the Grand Canyon, North Rim or South Rim, and probably one of the most gorgeous places on earth; if you can time your visit appropriately with a sunrise or sunset….words cannot adequately express the visual tour de force of the views. Reaching the overlook at trails end, you are meet by the twin, geologic spectacles of Wotan’s Throne and Vishnu Temple (Figure 2A.24), so close it seems you could reach out and touch them; Wotan’s Throne is the small, flat-topped mesa capped by Kaibab Limestone to the right, and Vishnu Temple is the pyramid-shaped pinnacle, capped by the Toroweap Formation, on the left. Looking further to the left, your view takes in Coconino Sandstone-capped Freya Castle as well (Figure 2A.25). Vishnu Temple and Freya Castle form isolated erosional remnants along a ridgeline deeply dissected by erosion along the Vishnu Fault (which runs down the axis of Vishnu Canyon and up the main stem of Unkar Creek Canyon). Taken together, one can only imagine the immense span of time needed for weathering processes and erosion to first isolate a mesa such as Wotan’s Throne from the rim, then slowly reduce it from tabletop to spire-tipped pyramid. These monoliths seem not to care as they stand guard over the watersheds of Vishnu Canyon and Unkar Creek Canyon which drain from the end of the Walhalla Plateau.
Figure 2A.24. An awe-inspiring view from Cape Royal overlook offers up the twin monoliths of Wotan’s Throne and Vishnu Temple
Figure 2A.25. Freya Castle and Vishnu Temple, isolated erosional remnants capped by Coconino Sandstone and Toroweap Formation respectively, lay southeast of Cape Royal overlook; the spires occupy a ridgeline deeply dissected by erosion along the Vishnu Fault.
Rise early if you want to catch a sunrise on Wotan’s Throne, it’s a long drive from campground or lodge (Figure 2A.26). Your Cape Royal vista will only be more memorable by the sight of the mesa, crowned in Kaibab Limestone and bathed in the orange-red glow of a rising sun; simply marvelous! Or, if you’d rather, remain until days end, the interplay of light and shadow, cloud formations, and varicolored rocky ramparts and deep defiles will always delight.
Figure 2A.26. Majestic Wotan’s Throne near daybreak; the summer storm in the background just made the sunrise more interesting.
As you head back to the Cape Royal parking area, make one more stop at a viewpoint to the left (west) side of the trail just past the fence line surrounding the Cape Royal overlook (about 80 yards back up the trail). This stop affords a spectacular view into an eastern tributary of Clear Creek (Figure 2A.27) and a distant view of the main Colorado River corridor of the central Grand Canyon. If you know what to look for, this viewpoint also offers an opportunity to observe sedimentary rocks of the Grand Canyon Supergroup. Look closely at the portion of main Clear Creek Canyon near its confluence with your eastern tributary (Figure 2A.28). The Tapeats Sandstone can be seen to form its typical rim around the inner gorge of the canyon, but also notice that the rocks exposed below the Tapeats are northeasterly tilted sedimentary rocks (these are Supergroup rocks). The erosion surface separating these layers is the Great Unconformity (indicated by a dashed line in the photograph). What is really interesting about this section of Clear Creek is the cliff exposed along the right-hand edge of the visible portion of the inner gorge (marked by an arrow in the photograph). This cliff-forming unit is not Tapeats Sandstone as might seem plausible, instead it is formed of Shinumo Sandstone, a resistant unit within the lower Unkar Group. In fact, the Tapeats Sandstone actually pinches out to the right against this resistant cliff and the Shinumo itself is only overlain by Bright Angel Shale. The Shinumo Sandstone cliff thus formed an “island” during the Middle Cambrian marine transgression (which eventually deposited the Tapeats – Bright Angel – Muav Limestone transgressive sequence exposed within the Grand Canyon) that was only inundated by rising sea level during Bright Angel deposition. This location is one of only two places in the Grand Canyon where you can observe such “islands in a Cambrian sea” from the rim (the other location is Moran Point on the South Rim). And best of all, you can hike to this very portion of the Clear Creek drainage to observe this amazing geology up close – see the Clear Creek Trail – Tr 2A.4 described in the Optional Hiking Trails section of Field Trip 1A).
Figure 2A.27. A view to the west down an eastern tributary of the Clear Creek drainage offers some unusual geology as well as spectacular scenery.
Figure 2A.28. A closer view of the main Clear Creek Canyon’s inner gorge as observed from near the Cape Royal overlook; the dashed line indicates the Great Unconformity and the arrow draws attention to tilted layers of the Shinumo Sandstone.
Return to your vehicle. If you have followed my guide to the letter from campground or lodge, you have seen enough visually stunning geology for one day (perhaps two?).
33.6 (14.1) Refer to Map 2A.4. Return to the intersection with the Fuller Canyon Road; if your time is limited, head back to AZ Hwy 67, otherwise continue north on the much shorter Imperial Point Road.
Road Route Maps
Map 2A.1. Color shaded-relief map of the Jacob Lake, AZ 7.5-minute quadrangle showing segments of Field Trip 2A, 2D, and 2E.
Map 2A.2. Color shaded-relief map of the Telephone Hill, AZ 7.5-minute quadrangle showing a segment of Field Trip 2A.
Map 2A.3. Color shaded-relief map of the De Motte Park, AZ 7.5-minute quadrangle showing segments of Field Trip 2A, 2B, 2C, and 2D.
Map 2A.4. Color shaded-relief map of the Little Park Lake, AZ 7.5-minute quadrangle showing segments of Field Trip 2A, 2B, and 2C.
Map 2A.5. Color shaded-relief map of the Bright Angel Point, AZ 7.5-minute quadrangle showing segments of Field Trip 2A and 2C.
Map 2A.6. Color shaded-relief map of the Point Imperial, AZ 7.5-minute quadrangle showing segments of Field Trip 2A, 2B, and 2E.
Map 2A.7. Color shaded-relief map of the Walhalla Plateau, AZ 7.5-minute quadrangle showing a segment of Field Trip 2A.
Map 2A.8. Color shaded-relief map of the Cape Royal, AZ 7.5 minute quadrangle showing a segment of Field Trip 2A.