Grand Canyon of the Yellowstone
Encyclopedia
The Grand Canyon of the Yellowstone is the first large canyon
on the Yellowstone River
downstream from Yellowstone Falls
in Yellowstone National Park
. The canyon is approximately 24 miles long, between 800 feet (244m) and 1,200 feet (366m) deep and between one quarter of a mile (.45km) and three quarters of a mile (1.2km) wide.
of 1870.
When Charles W. Cook first viewed the canyon after traveling west from the Lamar Valley
on September 20, 1869 he subsequently wrote these words in his journal:
A year later during the Washburn expedition, on August 30–31, 1870, Lt. Gustavus C. Doane
described the canyon with a bit more scientific detail:
In 1890, Bozeman
resident H.F. Richardson (known as Uncle Tom) was given a permit to operate a ferry across the Yellowstone River near the site of today's Chittenden Bridge and take tourists down into the canyon below the lower falls on Uncle Tom's Trail. Although the original trail no longer exists, there is still a steep stairway down to the base of the lower falls that is called Uncle Tom's Trail.
of the canyon are not well understood, except that it is an erosion
al feature rather than the result of glaciation. After the Yellowstone Caldera
eruption of about 600,000 years ago, the area was covered by a series of lava
flows. The area was also faulted by the doming action of the caldera
before the eruption. The site of the present canyon, as well as any previous canyons, was probably the result of this uplift and related fault
ing, which allowed erosion to proceed at an accelerated rate. The area was also covered by the glacier
s that formed during several ice age
s. Glacial deposits probably filled the canyon at one time, but have since been eroded away, leaving little or no evidence of their presence.
The canyon below the Lower Yellowstone Falls
was at one time the site of a geyser
basin that was the result of rhyolite
lava flows, extensive faulting, and heat beneath the surface (related to the hot spot). No one is sure exactly when the geyser basin was formed in the area, although it was probably present at the time of the last glaciation. The chemical and heat action of the geyser basin caused the rhyolite rock to become hydrothermally altered, making it very soft and brittle and more easily erodible (sometimes likened to baking a potato
). Evidence of this thermal activity still exists in the canyon in the form of geysers and hot spring
s that are still active and visible. The Clear Lake area, which is fed by hot springs, south of the canyon is probably also a remnant of this activity.
According to Ken Pierce, U.S. Geological Survey geologist, at the end of the last glacial period, about 14,000 to 18,000 years ago, ice dam
s formed at the mouth of Yellowstone Lake
. When the ice dams melted
, a great volume of water was released downstream causing massive flash flood
s and immediate and catastrophic erosion of the present-day canyon. These flash floods probably happened more than once. The canyon is a classic V-shaped valley
, indicative of river-type erosion rather than glaciation. Today the canyon is still being eroded by the Yellowstone River.
The color
s in the canyon are also a result of hydrothermal alteration. The rhyolite in the canyon contains a variety of different iron
compounds. When the old geyser basin was active, the "cooking" of the rock caused chemical alterations in these iron compounds. Exposure to the elements caused the rocks to change colors. The rocks are oxidizing; in effect, the canyon is rust
ing. The colors indicate the presence or absence of water in the individual iron compounds. Most of the yellows in the canyon are the result of iron present in the rock
rather than, as many people think, sulfur
.
Canyon
A canyon or gorge is a deep ravine between cliffs often carved from the landscape by a river. Rivers have a natural tendency to reach a baseline elevation, which is the same elevation as the body of water it will eventually drain into. This forms a canyon. Most canyons were formed by a process of...
on the Yellowstone River
Yellowstone River
The Yellowstone River is a tributary of the Missouri River, approximately long, in the western United States. Considered the principal tributary of the upper Missouri, the river and its tributaries drain a wide area stretching from the Rocky Mountains in the vicinity of the Yellowstone National...
downstream from Yellowstone Falls
Yellowstone Falls
Yellowstone Falls consist of two major waterfalls on the Yellowstone River, within Yellowstone National Park, Wyoming, United States. As the Yellowstone river flows north from Yellowstone Lake, it leaves the Hayden Valley and plunges first over Upper Yellowstone Falls and then a quarter mile ...
in Yellowstone National Park
Yellowstone National Park
Yellowstone National Park, established by the U.S. Congress and signed into law by President Ulysses S. Grant on March 1, 1872, is a national park located primarily in the U.S. state of Wyoming, although it also extends into Montana and Idaho...
. The canyon is approximately 24 miles long, between 800 feet (244m) and 1,200 feet (366m) deep and between one quarter of a mile (.45km) and three quarters of a mile (1.2km) wide.
History
Although trappers and prospectors who visited the Yellowstone region had knowledge of the canyon, the first significant descriptions were publicized after the Cook–Folsom–Peterson Expedition of 1869 and the Washburn-Langford-Doane ExpeditionWashburn-Langford-Doane Expedition
The Washburn Expedition of 1870, explored the region of northwestern Wyoming that a couple years later became Yellowstone National Park. Led by Henry Washburn, Nathaniel P. Langford and under U.S. Army escort led by Lt. Gustavus C...
of 1870.
When Charles W. Cook first viewed the canyon after traveling west from the Lamar Valley
Lamar River
The Lamar River is a tributary of the Yellowstone River, approximately 40 miles long, in northwestern Wyoming in the United States. The river is located entirely within Yellowstone National Park.-History:...
on September 20, 1869 he subsequently wrote these words in his journal:
I was riding ahead, the two pack animals following, and then Mr. Folsom and Mr. Peterson on their saddle horses. I remembered seeing what appeared to be an opening in the forest ahead, which I presumed to be a park, or open country. While my attention was attracted by the pack animals, which had stopped to eat grass, my saddle horse suddenly stopped. I turned and looked forward from the brink of the great canyon, at a point just across from what is now called Inspiration Point. I sat there in amazement, while my companions came up, and after that, it seemed to me that it was five minutes before anyone spoke.
A year later during the Washburn expedition, on August 30–31, 1870, Lt. Gustavus C. Doane
Gustavus Cheyney Doane
Gustavus Cheyney Doane was a U.S. Army Cavalry Captain, explorer, inventor and Civil War soldier who played a prominent role in the exploration of Yellowstone as a member of the Washburn-Langford-Doane Expedition.-Early life:...
described the canyon with a bit more scientific detail:
As we approached the Grand Cañon a dull roaring sound warned us that the falls were near at hand. ...I had descended the cañon at a point where the creek joined the river, precipitated into a gorge just above its juncture in a lovely cascade of three falls, in the aggregate 100 feet in height. This was named Crystal Cascade, and the stream Cascade Creek. In the bed of the gorge were to be found an infinite variety of volcanic specimens, quartz, feldspar, mica, granites, lavas, basalts, composite crystals; in fact, everything, from asbestos to obsidian, was represented by fragments in the bed of this stream. There were also beautiful clay stone specimens, of which we afterward learned the origin. At the foot of the gorge and on the margin of the Yellowstone stood a high promontory of concretionary lava, literally filled with volcanic butternuts. Many of these were loose, and could be taken out of the rock with the hand; broken open they were invariably hollow, and lined with minute quartz crystals of various tints. This formation is rare, but occurs frequently in the great basin. From the outer point of this promontory can be seen the foot of the upper fall of the Yellowstone, and I climbed to the summit to obtain a view.
In scenic beauty, the upper cataract far excels the lower. It has life, animation, while the lower one simply follows its channel; both, however, are eclipsed, as it were, by the singular wonders of the mighty cañon below. This deepens rapidly; the stream flowing over rapids continually. ...Several of the party descended into the chasm a short distance below the fall, but could not reach its foot. ... The walls of the cañon are of gypsum, in some places having an incrustation of lime white as snow, from which the reflected rays of the sun produce a dazzling effect, rendering it painful to look into the gulf. In others the rock is crystalline and almost wholly sulphur, of a dark yellow color, with streaks of red, green and black, caused by the percolations of hot mineral waters, of which thousands of springs are seen, in many instances, flowing from spouts high up on the walls on either side. The combinations of metallic lusters in the coloring of the walls is truly wonderful, surpassing, doubtless, anything of the kind on the face of the globe. The ground slopes to the cañon on the opposite or east side, and from it to the low valley on the west. Three miles below the fall the chasm is 1,050 feet deep. In some places masses of the rock have crumbled and slid down in a talus of loose material at the foot; in others, promontories stand out in all manner of fantastic forms, affording vistas of wonder utterly beyond the power of description. On the caps of these dizzy heights, mountain sheep and elk rest during the night. ...We had come down the ravine at least four miles, and looking upward the fearful wall appeared to reach the sky. It was about 3 o'clock p.m., and stars could be distinctly seen, so much of the sunlight was cut off from entering the chasm. Tall pines on the extreme verge appeared the height of two or three feet. The cañon, as before said, was in two benches, with a plateau on either side, about half way down. This plateau, about a hundred yards in width, looked from below like a mere shelf against the wall; the total depth was not less than 2,500 feet, and more probably 3,000. There are perhaps other canons longer and deeper than this one, but surely none combining grandeur and immensity with peculiarity of formation and profusion of volcanic or chemical phenomena.
In 1890, Bozeman
Bozeman, Montana
Bozeman is a city in and the county seat of Gallatin County, Montana, United States, in the southwestern part of the state. The 2010 census put Bozeman's population at 37,280 making it the fourth largest city in the state. It is the principal city of the Bozeman micropolitan area, which consists...
resident H.F. Richardson (known as Uncle Tom) was given a permit to operate a ferry across the Yellowstone River near the site of today's Chittenden Bridge and take tourists down into the canyon below the lower falls on Uncle Tom's Trail. Although the original trail no longer exists, there is still a steep stairway down to the base of the lower falls that is called Uncle Tom's Trail.
Important Canyon landmarks
- Agate Creek 44°51′01"N 110°21′38"W
- Artist Point 44°43′16"N 110°28′46"W
- Calcite Spring 44°54′24"N 110°23′42"W
- Cascade Creek 44°43′00"N 110°29′58"W
- Inspiration Point 44°43′31"N 110°28′13"W
- Grand View 44°43′36"N 110°28′48"W
- Lookout Point 44°43′24"N 110°29′03"W
- Overhanging Cliff 44°53′44"N 110°23′22"W
- Point Sublime 44°43′28"N 110°27′39"W
- Seven Mile Hole 44.75363°N 110.40450°W
- Silver Cord Cascade 44°43′34"N 110°27′06"W
Geology
The specifics of the geologyGeology
Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...
of the canyon are not well understood, except that it is an erosion
Erosion
Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...
al feature rather than the result of glaciation. After the Yellowstone Caldera
Yellowstone Caldera
The Yellowstone Caldera is the volcanic caldera located in Yellowstone National Park in the United States, sometimes referred to as the Yellowstone Supervolcano. The caldera is located in the northwest corner of Wyoming, in which the vast majority of the park is contained. The major features of...
eruption of about 600,000 years ago, the area was covered by a series of lava
Lava
Lava refers both to molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling. This molten rock is formed in the interior of some planets, including Earth, and some of their satellites. When first erupted from a volcanic vent, lava is a liquid at...
flows. The area was also faulted by the doming action of the caldera
Caldera
A caldera is a cauldron-like volcanic feature usually formed by the collapse of land following a volcanic eruption, such as the one at Yellowstone National Park in the US. They are sometimes confused with volcanic craters...
before the eruption. The site of the present canyon, as well as any previous canyons, was probably the result of this uplift and related fault
Geologic fault
In geology, a fault is a planar fracture or discontinuity in a volume of rock, across which there has been significant displacement along the fractures as a result of earth movement. Large faults within the Earth's crust result from the action of tectonic forces...
ing, which allowed erosion to proceed at an accelerated rate. The area was also covered by the glacier
Glacier
A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...
s that formed during several ice age
Ice age
An ice age or, more precisely, glacial age, is a generic geological period of long-term reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental ice sheets, polar ice sheets and alpine glaciers...
s. Glacial deposits probably filled the canyon at one time, but have since been eroded away, leaving little or no evidence of their presence.
The canyon below the Lower Yellowstone Falls
Yellowstone Falls
Yellowstone Falls consist of two major waterfalls on the Yellowstone River, within Yellowstone National Park, Wyoming, United States. As the Yellowstone river flows north from Yellowstone Lake, it leaves the Hayden Valley and plunges first over Upper Yellowstone Falls and then a quarter mile ...
was at one time the site of a geyser
Geyser
A geyser is a spring characterized by intermittent discharge of water ejected turbulently and accompanied by a vapour phase . The word geyser comes from Geysir, the name of an erupting spring at Haukadalur, Iceland; that name, in turn, comes from the Icelandic verb geysa, "to gush", the verb...
basin that was the result of rhyolite
Rhyolite
This page is about a volcanic rock. For the ghost town see Rhyolite, Nevada, and for the satellite system, see Rhyolite/Aquacade.Rhyolite is an igneous, volcanic rock, of felsic composition . It may have any texture from glassy to aphanitic to porphyritic...
lava flows, extensive faulting, and heat beneath the surface (related to the hot spot). No one is sure exactly when the geyser basin was formed in the area, although it was probably present at the time of the last glaciation. The chemical and heat action of the geyser basin caused the rhyolite rock to become hydrothermally altered, making it very soft and brittle and more easily erodible (sometimes likened to baking a potato
Potato
The potato is a starchy, tuberous crop from the perennial Solanum tuberosum of the Solanaceae family . The word potato may refer to the plant itself as well as the edible tuber. In the region of the Andes, there are some other closely related cultivated potato species...
). Evidence of this thermal activity still exists in the canyon in the form of geysers and hot spring
Hot spring
A hot spring is a spring that is produced by the emergence of geothermally heated groundwater from the Earth's crust. There are geothermal hot springs in many locations all over the crust of the earth.-Definitions:...
s that are still active and visible. The Clear Lake area, which is fed by hot springs, south of the canyon is probably also a remnant of this activity.
According to Ken Pierce, U.S. Geological Survey geologist, at the end of the last glacial period, about 14,000 to 18,000 years ago, ice dam
Ice dam
An ice dam occurs when water builds up behind a blockage of ice. Ice dams can occur in various ways.-Caused by a glacier:Sometimes a glacier flows down a valley to a confluence where the other branch carries an unfrozen river...
s formed at the mouth of Yellowstone Lake
Yellowstone Lake
Yellowstone Lake is the largest body of water in Yellowstone National Park, The lake is 7,732 feet above sea level and covers with 110 miles of shoreline. While the average depth of the lake is 139 feet its deepest spot is at least 390 feet...
. When the ice dams melted
Glacial lake outburst flood
A glacial lake outburst flood is a type of outburst flood that occurs when the dam containing a glacial lake fails. The dam can consist of glacier ice or a terminal moraine...
, a great volume of water was released downstream causing massive flash flood
Flash flood
A flash flood is a rapid flooding of geomorphic low-lying areas—washes, rivers, dry lakes and basins. It may be caused by heavy rain associated with a storm, hurricane, or tropical storm or meltwater from ice or snow flowing over ice sheets or snowfields...
s and immediate and catastrophic erosion of the present-day canyon. These flash floods probably happened more than once. The canyon is a classic V-shaped valley
Valley
In geology, a valley or dale is a depression with predominant extent in one direction. A very deep river valley may be called a canyon or gorge.The terms U-shaped and V-shaped are descriptive terms of geography to characterize the form of valleys...
, indicative of river-type erosion rather than glaciation. Today the canyon is still being eroded by the Yellowstone River.
The color
Color
Color or colour is the visual perceptual property corresponding in humans to the categories called red, green, blue and others. Color derives from the spectrum of light interacting in the eye with the spectral sensitivities of the light receptors...
s in the canyon are also a result of hydrothermal alteration. The rhyolite in the canyon contains a variety of different iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
compounds. When the old geyser basin was active, the "cooking" of the rock caused chemical alterations in these iron compounds. Exposure to the elements caused the rocks to change colors. The rocks are oxidizing; in effect, the canyon is rust
Rust
Rust is a general term for a series of iron oxides. In colloquial usage, the term is applied to red oxides, formed by the reaction of iron and oxygen in the presence of water or air moisture...
ing. The colors indicate the presence or absence of water in the individual iron compounds. Most of the yellows in the canyon are the result of iron present in the rock
Rock (geology)
In geology, rock or stone is a naturally occurring solid aggregate of minerals and/or mineraloids.The Earth's outer solid layer, the lithosphere, is made of rock. In general rocks are of three types, namely, igneous, sedimentary, and metamorphic...
rather than, as many people think, sulfur
Sulfur
Sulfur or sulphur is the chemical element with atomic number 16. In the periodic table it is represented by the symbol S. It is an abundant, multivalent non-metal. Under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a bright yellow...
.