As with my geological field guides to central Oregon, the primary intent of this set of guides to the Grand Canyon region is to summarize, in a travel log format, much of what is known about the geology of a uniquely fascinating landscape where a vast array of exemplary geologic features is on display. As before, I include accurate descriptions of how to reach many of the classical geological settings and features found in the area, either by car, bicycle, or on foot. As an avid outdoor enthusiast and professional geologist, I often take field trips with students that involve extended forays into the backcountry of the American southwest, one of my favorite “playgrounds” and a learning laboratory bar none! The goals of these excursions are certainly to learn geology, learn to recognize and interpret geological features and processes, learn the geological history of the Colorado Plateau, etc.; but an alternative goal is to teach my students how geologists do their work (and what they endure while doing so). I have many fond memories of camping, hiking, and backpacking in the wilds of the southwest with my enthusiastic, although often inexperienced students, while they were learning to think and act like field geologists. Through these adventures (ok, to be sure, not without some stress involved), I have gained a good deal of knowledge about the geology of the Grand Canyon region, and considerable personal experience doing geology under its breathtakingly beautiful, but often harsh conditions. These geological guides were conceived and written with the intent of sharing this knowledge and my personal experiences with a generalist audience of like-minded, out-of-doors adventure-seekers, inquisitive about natural history, but perhaps with a similarly limited background in geology and/or backcountry expertise as that of my students.
The ‘region’ in my use of the phrase Grand Canyon region represents a substantial piece of territory that is roughly centered on Grand Canyon National Park, both South and North Rims, but that also includes lands within the Kaibab National Forest and the Grand Canyon-Parashant National Monument to the north and west of Grand Canyon National Park proper (Figure 1). This region is veritably awash in a diverse array of fabulous geological phenomena; and their highly visible and for the most part accessible nature provides a significant motivation for adding the Grand Canyon region to my website. Few other places in the world offer such a plethora of outstanding landforms and exposures of rock and geological structures within easy reach. From your first glimpse of the canyon’s many-hued walls to your last heart-pounding view of its abyssal depths will come a profound sense of time; time is what it took to form the thick pile of sedimentary rock layers expressed in its cliffs and slopes, time is what it took to erode this region to its very core – twice!, and time is what is ticking now as the Colorado River and its tributaries carve a new landscape through those earlier pages of earth history. The sheer fecundity of the region’s exposed Proterozoic, Paleozoic, and Mesozoic sedimentary rock offers a mind-boggling variety of lithologies, sedimentary structures, and depositional environments to analyze and interpret. Faults and folds bisected by the Grand Canyon and its tributaries tell a story of the aggregation and breakup of continents, past mountain building events, and ongoing crustal extension. More recent Cenozoic-age volcanoes and their associated lava flows and pyroclastic materials abound on the northwest margins of the canyon, where many types of volcanoes and eruptive products are found. Some of these volcanoes show signs of recent eruptive activity; some can even be considered “active” by geological standards. And then there is the great mystery of the Grand Canyon’s carving in itself; its immensity proclaims a venerated status, and yet the geological evidence thus far gathered proclaims a more youthful vigor.
Figure 1. A map showing the Grand Canyon region as described in this series of guides; field trip routes are highlighted in color.
Each field trip guide begins with a brief ‘how to’ on their most efficient use, followed by some good advice for a safe and low impact outing. As an additional source of information, I have included a list of references that I have found useful in my teaching and wanderings about the canyon. Be sure to refer to the GEOLOGY BASICS and GEOLOGY OF THE GRAND CANYON REGION sections of my website for further information on the basic physical geology concerning many of the significant features that one may encounter in the field, as well as more detailed descriptions covering the geology of sedimentary rocks and the geology of the canyon’s Proterozoic crystalline basement and its geologic structures, both are highlighted in these field guides. Each field trip found in the FIELD GUIDES TO THE GRAND CANYON REGION is devoted to the description of a specific geological field area within the greater region (Figure 1), and is subdivided into two or more shorter excursions that include descriptive road logs detailing geological points of interest, descriptions of optional hiking trails that get you off road and closer to the action, and accompanying diagrams, photographs, and maps to aid your interpretation and navigation.
Preparation (Before You Head into the Field)
Any intended geological touring of the Grand Canyon region should begin with knowledge. For those of my readers that lack a background in geology, you are strongly encouraged to read the material covered in the GEOLOGY BASICS and GEOLOGY OF THE GRAND CANYON REGION sections of my website before embarking on any of the field trips described later in the FIELD GUIDES TO THE GRAND CANYON REGION’S GEOLOGY. Although these former sections of my website do not cover every aspect of the Grand Canyon region’s geologic features, they were developed to be as comprehensive as possible, without sacrificing readability and digestibility for the natural history enthusiast. The GEOLOGY BASICS section summarizes many fundamental concepts of physical geology, and describes numerous geologic features and processes significant to the Grand Canyon region’s geologic setting; it also provides a GLOSSARY OF GEOLOGIC TERMS. You may find that the first section of the webpage on the GEOLOGY OF CENTRAL OREGON, which focuses on features and processes related to volcanism would also be worth reading (especially for Field Trip 3).
The geological field guides presented in FIELD GUIDES TO THE GRAND CANYON REGION’S GEOLOGY are the heart and soul of the Grand Canyon portion of my website, their content should not be missed when planning an excursion into the area. Three field trip routes suffused with classical geological features are included (Figure 1): Field Trip 1 to the South Rim Area of Grand Canyon National Park; Field Trip 2 to the North Rim Area of Grand Canyon National Park; and Field Trip 3 to the Mount Trumbull Loop (including Tuweep Valley and Whitmore Wash of Grand Canyon National Park and Grand Canyon-Parashant National Monument). Each Field Trip is described in terms of auto-touring road logs, although they are readily adaptable to bike-touring; and all routes include descriptions of hiking trail options (for those seeking to get off the more beaten path). Each field trip road log is laid out in route segments with descriptive text, photos, figures, and accompanying topographic and/or geologic maps. For each route segment, the mileage between adjacent segments is provided, as well as the cumulative mileage for the entire route. As an example, specific locations or geologic features on a road log might be given as 12.3 (3.4), meaning that the total distance from the route’s starting location is 12.3 miles, and that the distance from the previously described mile-marker is 3.4 miles.
Route segments each follow a designated road generally suitable for passenger cars (much of Field Trip 3 being the exception), but many segments include options for hiking on trails to explore geologic features unreachable by car. These road routes would also be suitable for bike touring, although some routes or portions of routes may be better suited to off-road bikes. Road surfaces along the routes vary from pavement to packed earth (dirt). Roads surfaced with crushed rock, gravel or dirt can be dusty and rough depending on usage and maintenance; a not-so-pleasant phenomena known as “washboarding” is a common feature on gravel roads, especial if not recently graded. All limited-maintenance gravel roads were driven by passenger car during preparation of this guidebook, but care should be taken when driving these roads depending on the type of vehicle in use and the driver’s experience. Portions of Field Trip 2 and 3 are over unmaintained packed earth and sometimes even rugged outcroppings of rock and should only be driven with high clearance and/or 4-wheel drive vehicles. Descriptive text in the field trip road logs includes advisements on current rough road conditions, although be aware that some roads are poorly maintained or not maintained at all, thus ‘current’ conditions described on this website will become dated with time. Be sure to carry a spare tire, and adequate gas, food, water, and camping gear for emergencies; and check local accessibility on secondary roads prior to departure in late fall, winter, and early spring. A cell-phone is useful in many areas, but reception is spotty at best on portions of all three field trips (especially in the area covered by Field Trip 3).
Each field trip route description is accompanied by color shaded-relief map reproductions set to a scale of 1:24,000 (the same scale used on USGS 7.5-minute topographic quadrangles). Each map contains the road route currently being described, plus mile-markers for each route segment that indicate points of interest detailed in the road log’s text. Figure 2 provides a key to the route symbols used on the auto-touring route maps. Auto-touring route maps are located at the end of each field trip’s road log description. Route descriptions on federal and state highways, county roads, Forest Service and Bureau of Land Management roads are given in tenths of miles from certain easily located road intersections and from previously described features along the route (hiking trail distances are given in to the nearest hundredth of a mile); road and hiking trail mileage was obtained using a Garmin P-66. Many sites are described with reference to significant landmarks, geographic features, or milepost markers located at specific intervals along the edge of most roadways. Route descriptions also use standard compass bearings (such as northeast, southwest) and/or hourly positions on a clock (assuming 12:00 is due north) to indicate where to look for certain geological features. For example, a description may read “feature located to the east” or “feature located at 3:00”, indicating that the feature at hand can be readily observed from a certain road position when looking directly to your right. Route descriptions also use various abbreviations: BLM = U.S. Bureau of Land Management, FS = U.S. Forest Service, Hwy = highway, Rd = road, and Tr = trail. In this case, a road intersection might read as “The intersection of FS Rd 14 and county Rd 12A”.
Figure 2. Symbols used on field trip road and hiking trail route maps described in FIELD GUIDES TO THE GRAND CANYON’S GEOLOGY.
Hiking trail route maps accompany the descriptions of each optional hiking trail. Each map uses a geologic map base modified from existing 1:100,000 scale USGS geologic map data. The hiking trail route and mile markers describing points of interest are superimposed on the geologic base map. Rock units and geologic structures found on the hiking trail maps are described in the section of this website entitled INTERPRETATION OF TOPOGRAPHIC AND GEOLOGIC MAPS. PDF files of the complete hiking trail map can be downloaded from this website’s HIKING TRAIL MAP STORE. The “front side” of the map display’s the entire hiking trail route superimposed on the geologic base map, while the “back side” of the map includes the complete hiking trail route description (the same description found on the website).
Maps showing the general topography and all roads in the area can be obtained from the U.S. Forest Service, U.S. Park Service, and U.S. Bureau of Land Management. Several types of maps at a variety of scales, drawn at different levels of detail depending on their purpose, can be obtained from agency visitor centers, but particularly useful is the Kaibab National Forest North Kaibab Ranger District recreation map which includes much of the area described for the North Rim of the Grand Canyon. National Geographic offers its Trails Illustrated topographic map series which covers most areas described on my website; these are reasonably priced and conveniently waterproof and tear resistant. The U.S. Geological Survey also publishes standard 1:24,000 scale, 7.5 minute topographic maps of the entire United States; the USGS 7.5 minute quadrangle coverage for each field trip auto-touring route is indicated in that field trip’s introduction and the author encourages readers to obtain copies of these original topographic maps if greater detail is desired. Also recommended are copies of the Falcon Guide, Hiking Grand Canyon National Park, 4th edition (Adkison and Adkison, 2020), as well as Hiking the Grand Canyon’s Geology (Abbott and Cook, 2004); many great hikes are described in these pages, and the guidebooks include a treasure-trove of information on the regional geography and geology, along with camping and hiking regulations, safety tips, and etiquette.
Backcountry Safety and Responsibility
During the preparation of these field guides, I was keenly aware that my backcountry experiences are probably a tad greater than average, and that my environmental ethics might be honed to a greater degree of sensitivity than the typical weekend camper. Any adventure into the “wilds” of the southwest should not be taken lightly. Anyone who spends a significant time in the out-of-doors knows that doing so comes with a certain level of personal risk and potential environmental impact. Enjoy, but do so wisely, carefully, and respectfully.
Hiking in the Grand Canyon is both exhilarating and potentially frightening; for many novice canyoneers, overestimating what can comfortably be accomplished in a day is unfortunately, fairly commonplace. Nearly all of the Grand Canyon’s trails begin on the rim and descend 4,000 to 6,000 feet to the Colorado River, a dizzying change in elevation in itself, but also one that must be regained to return to the rim. Descending is normally fairly easy, so these trails have a tendency to lure hikers deeper into the canyon than they are prepared for (in terms of water, food, and gear), especially given that distances tend to be telescoped by the clear desert air. Novice hikers can make mistakes in preparation and in judgments made on the trail. Once in the canyon, its walls can enfold you, the vast distances overwhelm your senses, the heat and glare of the sun are punishing, and suddenly your canyon experience can become unnerving; there is no substitute for a positive mental attitude, proper physical conditioning, and a solid grasp of your limitations.
My safety suggestions are simple. First, carefully plan your itinerary; these field guides should aid you well in this endeavor. Second, make sure someone knows approximately where you’ll be and when you’ll be there, so that the authorities can be notified if you fail to appear. If you get into trouble, stay put, stay warm and dry, and someone will find you. Third, don’t do anything that you don’t feel comfortable doing because in all likelihood, it falls outside your realm of knowledge and skills, or it is inherently dangerous. Taking risks can be rewarding, but too much of a good thing can get you in harm’s way fast. Fourth, know what you are about when you head into the field, or take someone with you who does. While I have tried to describe each hiking route in detail, including the rather excellent maps contained within the field guides, my descriptions and maps should not be considered a substitute for good map reading and route finding skills. I have deliberately avoided using trail ratings in my field guides; the fact that a hike is included in these guides, no matter what rating I might give it, does not mean it will be safe or easy for you. And don’t be overly reliant on your hand-held GPS either, satellite signals can be poor in dense forest and rough terrain, and batteries can fail. Figure 3 offers index maps to the original USGS 7.5 minute topographic maps covered by each field trip in the Grand Canyon region; and of course, there is no substitution for the originals when planning and executing an excursion into central Oregon’s wild areas. Fifth, carry the right equipment. Travel in out of the way places can be challenging enough, but rough weather or a wrong turn can make the proper gear a lifesaving prospect. The ten essentials you should have in your backpack include: 1) plenty of drinking water – four liters per day minimum for desert hiking; 2) extra food; 3) a first aid kit; 4) a flashlight or headlamp; 5) fire-making materials (fire-starter and water-proofed matches or a butane lighter) – fires are not permitted in backcountry areas of Grand Canyon National Park; 6) rain gear; 7) a topographic map; 8) a compass – or GPS with good batteries; 9) a pocket knife; and 10) emergency shelter and/or extra clothing. Notice that a cell-phone didn’t make my list; cell-phone signals are spotty at best in much of the backcountry of the Grand Canyon region. Encounters with large wild animals are extremely rare in this area; nuisance rodents on the other hand are quite common. Mice and squirrels raiding your food can be avoided by using proper storage containers (I use 5-quart tin paint cans which can be easily pried open and resealed). Mosquitoes can be a problem until several weeks after snowmelt on the forested North and South Rims, so expect them at least through late-May at higher elevations. Travel by car may be inherently safer, but not without risk. Some locations in these field guides are a long way from anywhere, so in addition to the supplies above, bring an extra key to carry with you when you leave the vehicle, and bring plenty of extra water and a good spare tire for the vehicle too (no donuts please!).
Please minimize your impact when travelling in the backcountry; personally, I recommend following Leave No Trace principles (www.lnt.org): 1) plan ahead and prepare; 2) hike and camp on durable surfaces; 3) dispose of waste properly; 4) leave what you find; 5) minimize campfire and camping area impacts; 6) respect wildlife; and 7) be considerate of other visitors. Hike on established trails whenever possible, and do not shortcut switchbacks or “trail” around mud, standing water, or snow-covered patches. In areas where there are no established trails, avoid trammeling on delicate desert vegetation (and especially cryptobiotic soils!) whenever possible by using rock outcrops, stones, or dry grasses if need be. Choose a campsite well away from trails, streams, and shorelines, preferably in an established location; and never on meadow vegetation. Avoid campfires (they are illegal in Grand Canyon backcountry designated as Wilderness); cook with a camp stove and wash at least 100 feet from the water’s edge. Please pack out all of your trash (even some “organic” material such as orange peels can take years to decompose; and the natives don’t need to eat your leftovers anyway). Consumption of edible berries is certainly a perk of your outdoor adventuring, but don’t pick the wildflowers or carve your name in the trees please. And special rules do apply to designated Wilderness Areas (some areas within Canyon National Park, Canyon-Parashant National Monument, and Kaibab National Forest). From the last weekend in May through the end of October, a hiking/backpacking permit is required for certain Wilderness Area locations (inquire at the relevant National Forest website or ranger’s station). Many other restrictions pertain to camping in Wilderness Areas and should be observed: 1) groups must be 12 people or less; 2) camp in designated sites only if available; 3) no campfires within 100 feet of trails or water; 4) do not enter rehabilitation areas; 5) bicycles and other wheeled vehicles (except wheelchairs), motorized equipment, and fireworks are not permitted; 6) riding horses and pack stock cannot be tethered within 200 feet of water; and 8) do not cut or damage live trees and shrubs. Collecting plants is by permit only, and the collection of cultural artifacts (arrowheads and the like) is a crime on all federal lands.
Backcountry Use Permits (Grand Canyon National Park)
A backcountry permit is required for overnight hiking in Grand Canyon National Park, and overnight car-camping at several locations on the South and North Rims. The process for obtaining a permit may initially seem quirky and burdensome (perhaps it is, this discourages the weekend warriors), but in all fairness to the national park, regulating trail and campsite use is a necessary management tool to prevent resource degradation (80% of money collected is used directly for backcountry programs).
Backcountry Use Permits are obtained from the park’s Backcountry Information Center either in person, by fax, or by mail. Currently, these permits cost $10.00, plus $8.00 per night, per person. General information on trail conditions, campsite availability, etc. can be obtained by phone (928-638-7875), but not permits. The main information center, at the South Rim, is open 8:00am till noon, and 1:00 till 5:00pm seven days a week (the North Rim Backcountry Information Center is located in the administrative building and is open daily mid-May to mid-October for walk-in visitors from 8:00am till noon and 1:00 till 5:00pm Mountain Standard Time). Up-to-date information and a PDF file of the permit request form can be found at www.nps.gov/grca; follow the links for “Backcountry Hiking” and “Backcountry Permit”. When filling out the permit, you’ll need to indicate starting and ending trailheads, nightly designated campsites (or designated camping areas) during your trek, the length of your outing, and the number of members in your party. Plan ahead, the park begins accepting faxed and mailed-in requests starting about 10 days before the first of the month that is four months prior to the month of the proposed start date. All earliest consideration requests received by 5pm Mountain Standard Time on the first of the month are randomly ordered for processing (Table 1). Once this is completed all later requests are considered in the order received. It’s a good idea to submit several optional trips; overnight hikes in the park are quite popular! You can indicate optional start dates and number of party members for a given trip as well. Once you have filled out the form, fax it to the information center (928-638-2125), or mail it to Grand Canyon National Park, Permits Office, 1824 S. Thompson St., Suite 201, Flagstaff AZ, 86001. The park also maintains a limited number of last minute walk-in permits for Corridor Campgrounds (Indian Garden, Bright Angel, and Cottonwood Campgrounds) that are available at the South Rim and/or North Rim Backcountry Information Centers. These permits are issued in person only, are for one or two consecutive nights, and cannot be purchased more than one day prior to the start of a hike. Last minute permits are issued by the Backcountry Information Center, located inside the park on both the South Rim and the North Rim.
Table 1: Backcountry Use Permit Request Dates (Grand Canyon National Park website)
|For hike dates during the month of:||Submit written requests starting:||Requests received by 5pm MST on this day get earliest consideration:||In-person verbal requests accepted on or after:|
|January||Aug 20||Sep 1||Oct 1|
|February||Sep 20||Oct 1||Nov 1|
|March||Oct 20||Nov 1||Dec 1|
|April||Nov 20||Dec 1||Jan 1|
|May||Dec 20||Jan 1||Feb 1|
|June||Jan 20||Feb 1||Mar 1|
|July||Feb 20||Mar 1||Apr 1|
|August||Mar 20||Apr 1||May 1|
|September||Apr 20||May 1||Jun 1|
|October||May 20||Jun 1||Jul 1|
|November||Jun 20||Jul 1||Aug 1|
|December||Jul 20||Aug 1||Sep 1|
There are no fees, permits, or reservations required in Grand Canyon-Parashant National Monument (pertinent to Field Trip 3), although much of the area is managed as wilderness, so tread lightly and only drive or hike on established roads and routes. This is wild country; there are no paved roads or visitor services within the monument. There are few established hiking trails, and visitors should be prepared for travel on rugged dirt roads. Traveling with an appropriate high clearance, 4-wheel drive vehicle equipped with 8-ply or 10-ply tires or with two full-sized spare tires is recommended. Current information about the monument can be found at www.nps.gov/para; the Interagency Visitor Center located at 345 East Riverside Drive in St. George, UT (call 435-688-3200) is your best bet for up-to-date information on road conditions.
Are you ready to get out there? Don’t forget to pack your guide. Please drive and hike safely; slow down, and get out of your car often; take a hike, brave the elements, work up a sweat, and get your hands dirty. It’s the only way to SEE the world!