The Firehole River is located in northwestern

Wyoming Wyoming () is a state in the Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to t ...

, and is one of the two major

tributaries A tributary, or affluent, is a stream or river that flows into a larger stream or main stem (or parent) river or a lake. A tributary does not flow directly into a sea or ocean. Tributaries and the main stem river drain the surrounding drain ...

of the

Madison River The Madison River is a headwater tributary of the Missouri River, approximately 183 miles (295 km) long, in Wyoming and Montana. Its confluence with the Jefferson and Gallatin rivers near Three Forks, Montana forms the Missouri River. Th ...

. It flows north approximately from its source in Madison Lake on the

Continental Divide A continental divide is a drainage divide on a continent such that the drainage basin on one side of the divide feeds into one ocean or sea, and the basin on the other side either feeds into a different ocean or sea, or else is endorheic, not c ...

to join the Gibbon River at Madison Junction in

Yellowstone National Park Yellowstone National Park is an American national park located in the western United States, largely in the northwest corner of Wyoming and extending into Montana and Idaho. It was established by the 42nd U.S. Congress with the Yellowst ...

. It is part of the Missouri River system.

Description

The Firehole River flows through several significant geyser basins in Yellowstone National Park to include the

Upper Geyser Basin The geothermal areas of Yellowstone include several geyser basins in Yellowstone National Park as well as other geothermal features such as hot springs, mud pots, and fumaroles. The number of thermal features in Yellowstone is estimated at 10,0 ...

, which contains the world-famous geyser

Old Faithful Old Faithful is a cone geyser in Yellowstone National Park in Wyoming, United States. It was named in 1870 during the Washburn–Langford–Doane Expedition and was the first geyser in the park to be named. It is a highly predictable geotherm ...

. The river was named by early trappers for the steam that makes it appear to be smoking as if on fire. The Firehole flows over three of Yellowstone's major

waterfalls A waterfall is a point in a river or stream where water flows over a vertical drop or a series of steep drops. Waterfalls also occur where meltwater drops over the edge of a tabular iceberg or ice shelf. Waterfalls can be formed in several w ...

: Kepler Cascades south of Old Faithful, Firehole Falls and the Cascades of the Firehole in Firehole Canyon. The river is surrounded by geothermal features which empty water into it. One effect of the input of this water is to increase the temperature of the water. Temperatures in the river have been measured as high as and average 5 to 10 °C (9 to 18 °F) higher than areas upstream of geothermal influence. Water entering the river from geothermal features contains dissolved chemicals and minerals. Levels of

boron Boron is a chemical element with the symbol B and atomic number 5. In its crystalline form it is a brittle, dark, lustrous metalloid; in its amorphous form it is a brown powder. As the lightest element of the '' boron group'' it has t ...

and

arsenic Arsenic is a chemical element with the symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, b ...

have been found to be above the standard limits for protection of aquatic organisms. Despite these levels,

brown Brown is a color. It can be considered a composite color, but it is mainly a darker shade of orange. In the CMYK color model used in printing or painting, brown is usually made by combining the colors orange and black. In the RGB color model ...

and

rainbow trout The rainbow trout (''Oncorhynchus mykiss'') is a species of trout native to cold-water tributaries of the Pacific Ocean in Asia and North America. The steelhead (sometimes called "steelhead trout") is an anadromous (sea-run) form of the coast ...

live and spawn in the river. The river contains an

invasive species An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species adv ...

, the

New Zealand mud snail The New Zealand mud snail (''Potamopyrgus antipodarum'') is a species of very small freshwater snail with a gill and an operculum. This aquatic gastropod mollusk is in the family Tateidae. It is native to New Zealand, where it is found throug ...

(''Potamopyrgus antipodarum'').

Tributaries

Significant tributaries of the Firehole are the Little Firehole River, Fairy Creek, Iron Spring Creek, Sentinel Creek and Nez Perce Creek. All these tributaries bring cool waters to the Firehole and provide refuge for trout in the mainstem during mid-summer high temperatures caused by geothermal activity.

Angling

The Firehole River is a famous and storied destination for serious fly fishermen. When it was discovered in the 1830s by American explorers, the Firehole was barren of trout above what is now called Firehole Falls.

Brook trout The brook trout (''Salvelinus fontinalis'') is a species of freshwater fish in the char genus ''Salvelinus'' of the salmon family Salmonidae. It is native to Eastern North America in the United States and Canada, but has been introduced elsewhere ...

were first introduced to the upper Firehole in 1889, while

brown trout The brown trout (''Salmo trutta'') is a European species of salmonid fish that has been widely introduced into suitable environments globally. It includes purely freshwater populations, referred to as the riverine ecotype, ''Salmo trutta'' morp ...

, the river's most plentiful trout today, was first stocked in 1890.

Rainbow trout The rainbow trout (''Oncorhynchus mykiss'') is a species of trout native to cold-water tributaries of the Pacific Ocean in Asia and North America. The steelhead (sometimes called "steelhead trout") is an anadromous (sea-run) form of the coast ...

were not introduced until 1923.

Mountain whitefish The mountain whitefish (''Prosopium williamsoni'') is one of the most widely distributed salmonid fish of western North America. It is found from the Mackenzie River drainage in Northwest Territories, Canada south through western Canada and ...

are native to the Firehole below Firehole Falls. By the late 19th century, the Firehole and Yellowstone National Park in general was a popular destination for fishermen. In 1955 all stocking programs in the park were discontinued and today's Firehole trout are completely wild populations. In 1968, based on increasing pressure on the Firehole, the Gibbon and Madison rivers, the

National Park Service The National Park Service (NPS) is an agency of the United States federal government within the U.S. Department of the Interior that manages all national parks, most national monuments, and other natural, historical, and recreational properti ...

designated these waters as Fly Fishing Only.

Description

Tributaries

Angling

Gallery

See also

References

Further reading