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geology fieldnotes title

Black Canyon of the Gunnison

National Park


cover of park brochure

park geology subheading
Pituresque photo of the Black Canyon from above
Black Canyon of the Gunnison, Colorado

Our surroundings were of the wildest possible description. The roar of the water . . . was constantly in our ears, and the walls of the canon, towering half mile in height above us, were seemingly vertical. Occasionally a rock would fall from one side or the other, with a roar and crash, exploding like a ton of dynamite when it struck bottom, making us think our last day had come. - Abraham Lincoln Fellows, 1901

The canyon's landscape was formed by the slow, but continuous and unyielding process of erosion—the effect of one drop of water at a time or the scouring by a seasonally flood-swollen river, the rush of mud-laden side streams after heavy rains, occasional rockfalls from high cliffs, and the relentless creep of landslides. The river first established its course over soft volcanic rock. It then cut through this rock to the harder and older crystalline rock of the present canyon that had been thrust up in an earlier dome-shaped formation known as the Gunnison Uplift. Once committed to its course, the stream had no alternative but to continue to cut through this once-buried hard core, taking about two million years to carve the gorge. The excavating process is still going on, but at a slower pace because of the dams upstream.

An Awesome Gorge
"Several western canyons exceed the Black Canyon in overall size", Wallace Hansen wrote after studying the geology of the region for a number of years. "Some are longer, some are deeper, some are narrower, and a few have walls as steep. But no other canyon in North America combines the depth, narrowness, sheerness, and somber countenance of the Black Canyon of the Gunnison". And it is largely because of this unique combination of geologic features that the Black Canyon has been preserved in its wild state.

block diagramThe Gunnison River within the Black Canyon drops an average of 95 feet per mile (18 meters per kilometer). This is one of the greatest rates of fall for a river in North America. The diagram covers the 12 miles (19 kilometers) of the river within the park.

The Black Canyon, which has been carved by the Gunnison River as it hurries to join the Colorado, is 53 miles long, but only the deepest, most spectacular 12 miles of the gorge lie within Black Canyon of the Gunnison National Park. Slanting rays of sunlight penetrate this deep and narrow canyon's dark gray walls of schist and gneiss that are shrouded in heavy shadows most of the day—hence, "Black Canyon". East of the park the Gunnison River has been impounded and tamed behind three dams. In the Black Canyon, however, it remains one of the few unspoiled wild rivers in the country.

The canyon and its rims are home to a variety of wildlife, from the chipmunks and ground squirrels to weasels, badgers, marmots, and black bear. Infrequently bobcat and cougars are sighted, and at night, coyotes may be heard. If you come across trees that have been gnawed on, you will have found evidence that porcupines are thereabouts, for the bark of pine and oak is a favored winter food of this quill-covered rodent. The Gambel oak and serviceberry that cover most of the Gunnison Uplift provide a good habitat for towhees, western tanagers, pinyon and scrub jays, and black-billed magpies. The cliffs are home to white-throated swifts, violet-green swallows, golden eagles, turkey vultures, and red-tailed hawks, who all take advantage of the updrafts for soaring. The endangered peregrine falcon also finds protection and feathered prey here.

    Though a home to wildlife, the canyon has been a mighty barrier to human beings.
  • Archeological evidence indicates that pre-historic man, and later the Utes, used only the canyon rims, never living in the gorge.

  • The first white men to see the great chasm actually were members of the Hayden Expedition in 1873-74.

  • It appears that the Spaniards, including the famed Dominguez- Escalante Expedition in 1776, all missed seeing the canyon as they came over the Uncompahgre Plateau and into the Uncompahgre Valley on various journeys of exploration.

  • Even the group led by Capt. John W. Gunnison, whose name has become permanently attached to the river, bypassed the gorge itself in its search for a river crossing.

  • The Hayden Expedition and later surveying parties for the Denver & Rio Grande Railroad all pronounced the Black Canyon "inaccessible".

By the last decade of the 19th century there was much interest in tapping the Gunnison River as a source of water for the Uncompahgre Valley. In 1900 five valley men made a heroic effort to float through the canyon with surveying equipment, but after a month's effort, they had to admit defeat. In 1901 William Torrence and Abraham Lincoln Fellows, learning a lesson from the previous trip, took a rubber mattress for a raft, arranged to be supplied at various points from the rim, and were able to make their way through the canyon—33 miles in nine days. From the engineering log the two men kept, it was obvious that an irrigation tunnel was a feasible project. In January 1905 construction work began on the diversion tunnel. Progress was slow because of the many difficulties that the work crews encountered. Intense heat, violent cascades of water, and unstable rock formations were just a few of the problems the engineers had to deal with. When finished the tunnel measured 5.8 miles long and could carry enough water to irrigate a sizable farming community. Eight years after Torrence and Fellow's trip, on September 23, 1909, President William Howard Taft presided over the dedication ceremonies for the Gunnison Diversion Tunnel, a notable engineering achievement of this or any time.

In the late 1920s, citizens of Montrose and other area towns, led by Rev. Mark T. Warner and local civic groups, began efforts to have the scenic beauty of the canyon preserved as a part of the National Park System. On March 2, 1933, President Herbert Hoover proclaimed Black Canyon of the Gunnison National Monument. Since that time, thousands have enjoyed the scenic grandeur of Black Canyon. A smaller number of hardy individuals have hiked to the bottom of the canyon for fishing, rock climbing, and camping. A portion of the Black Canyon of the Gunnison National Park is classified as wilderness now in an attempt to ensure that the landscape will remain forever in its natural state.

The Painted Wall is the result of molten material forced under great pressure into the cracks and joints of the base rock. Those sheer walls are an ideal home for the peregrine falcon. Perhaps you will be fortunate enough to see one.

Your time in the park can be spent in a number of ways (left): enjoying a nature talk viewing the canyon from the North Rim Drive, or hiking down to the river at the bottom of the canyon. Should you choose to hike into the canyon, check first with a ranger.

cover of scoping reportBlack Canyon of the Gunnison National Park and Curecanti National Recreation Area: Geologic Resource Evaluation Report

park maps subheading

The General park map handed out at the visitor center is available on the park's map webpage.

View the park's map to create your own personal maps and images right here.

For information about topographic maps, geologic maps, and geologic data sets, please see the geologic maps page.

photo album subheading

A geology photo album for this park can be found here.

For information on other photo collections featuring National Park geology, please see the Image Sources page.

books, videos, cds subheading

Currently, we do not have a listing for a park-specific geoscience book. The park's geology may be described in regional or state geology texts.

Please visit the Geology Books and Media webpage for additional sources such as text books, theme books, CD ROMs, and technical reports.

Parks and Plates: The Geology of Our National Parks, Monuments & Seashores.
Lillie, Robert J., 2005.
W.W. Norton and Company.
ISBN 0-393-92407-6
9" x 10.75", paperback, 550 pages, full color throughout

The spectacular geology in our national parks provides the answers to many questions about the Earth. The answers can be appreciated through plate tectonics, an exciting way to understand the ongoing natural processes that sculpt our landscape. Parks and Plates is a visual and scientific voyage of discovery!

Ordering from your National Park Cooperative Associations' bookstores helps to support programs in the parks. Please visit the bookstore locator for park books and much more.

geologic research subheading

Information about the park's research program and partnerships is available on the park's research webpage.

For information about permits that are required for conducting geologic research activities in National Parks, see the Permits Information page.

The NPS maintains a searchable data base of research needs that have been identified by parks.

A bibliography of geologic references is being prepared for each park through the Geologic Resources Evaluation Program (GRE). Please see the GRE website for more information and contacts.

selected links subheading

NPS Geology and Soils Partners

NRCS logoAssociation of American State Geologists
NRCS logoGeological Society of America
NRCS logoNatural Resource Conservation Service - Soils
USGS logo U.S. Geological Survey

teacher feature subheading

Black Canyon of the Gunnison National Park and Curecanti National Recreation Area Outreach Education Programs are committed to creating an awareness of and fostering an appreciation for the mission of the National Park Service and the natural, cultural, and historic resources of the two parks.

General information about the park's education and intrepretive programs is available on the park's education webpage.

For resources and information on teaching geology using National Park examples, see the Students & Teachers pages.
updated on 01/04/2005  I   http://www.nature.nps.gov/geology/parks/blca/index.cfm   I  Email: Webmaster
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