Spearfish_Canyon_falls_Black_Hills_NF_Oct_2018

Spearfish Canyon is a deep but narrow

gorge A canyon (; archaic British English spelling: ''cañon''), gorge or chasm, is a deep cleft between escarpments or cliffs resulting from weathering and the erosion, erosive activity of a river over geologic time scales. Rivers have a natural tend ...

carved by Spearfish Creek located in Lawrence County,

South Dakota South Dakota (; Sioux language, Sioux: , ) is a U.S. state, state in the West North Central states, North Central region of the United States. It is also part of the Great Plains. South Dakota is named after the Dakota people, Dakota Sioux ...

U.S. The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 states and a federal capital district, Washington, D.C. The 48 contiguous ...

, just south of

Spearfish Spearfish may refer to: Places * Spearfish, South Dakota, United States * North Spearfish, South Dakota, United States * Spearfish Formation, a geologic formation in the United States Biology * ''Tetrapturus'', a genus of marlin with shorter ...

. The canyon is located within the Black Hills, located on the northern edge of the

Black Hills National Forest Black Hills National Forest is located in southwestern South Dakota and northeastern Wyoming, United States. The forest has an area of over 1.25 million acres (5,066 km2) and is managed by the Forest Service. Forest headquarters are located ...

. The Spearfish Canyon Scenic Byway travels through the Canyon from

to Cheyenne Crossing along U.S. Route 14A. The highway follows an old railroad grade that was abandoned after massive flooding in 1933.

Natural history

Approximately 600 million years ago in the

Precambrian The Precambrian ( ; or pre-Cambrian, sometimes abbreviated pC, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of t ...

, the area was covered by a sea. As waters subsided and land masses began to appear 60 to 30 million years ago (between the

Paleocene The Paleocene ( ), or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), ...

and

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

epochs), drainages such as Spearfish Canyon formed as softer rock was eroded away. Today, a

National Scenic Byway A National Scenic Byway is a road recognized by the United States Department of Transportation for one or more of six "intrinsic qualities": archeological, cultural, historic, natural, recreational, and scenic. The program was established by Co ...

, U.S. Route 14A, winds through the canyon. This area is truly a crossroads, and trees and plants from Rocky Mountains, eastern woodlands, northern forests, and the Great Plains areas can be found here.

Flora and fauna

Of the 1,585 plant species found in South Dakota, 1,260 species are in the Black Hills, many of which can be found in Spearfish Canyon.

Ponderosa pine ''Pinus ponderosa'', commonly known as the ponderosa pine, bull pine, blackjack pine, western yellow-pine, or filipinus pine, is a very large pine tree species of variable habitat native to mountainous regions of western North America. It is t ...

s are the most prominent vegetation in the Black Hills. As for bird species, turkeys, bluejays, woodpeckers, cliff swallows, chickadees, and golden or bald eagles are seen in the area. The canyon supports a cross-section of four-footed animal life. White-tail and mule deer can be found throughout the drive. Porcupines, raccoons, squirrels, and chipmunks might be spotted as well as a bobcat or a

yellow-bellied marmot The yellow-bellied marmot (''Marmota flaviventer''), also known as the rock chuck, is a large, stout-bodied ground squirrel in the marmot genus. It is one of fourteen species of marmots, and is native to mountainous and semi-arid regions of south ...

Geology

It is often studied by geologists due to the extreme old age of the Precambrian rocks exposed by the creek bed. The canyon's high walls are of three dominant rock types. The

Cambrian The Cambrian ( ) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordov ...

Ordovician The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era, and the second of twelve periods of the Phanerozoic Eon (geology), Eon. The Ordovician spans 41.6 million years f ...

Deadwood Shale at the bottom lies on an

unconformity An unconformity is a buried erosional or non-depositional surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval ...

above Precambrian rock and can be identified by its brown color. It is multi-layered in appearance and ranges from to thick. Englewood Limestone in the middle is pink to red colored and is to thick. The

Paleogene The Paleogene Period ( ; also spelled Palaeogene or Palæogene) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period Ma (million years ago) to the beginning of the Neogene Period Ma. It is the fir ...

Paha Sapa Limestone, the top layer, is the thickest ( to ) and is buff-colored and weathered gray in appearance. Caves and fossils are frequently found in the Paha Sapa Limestone.

References

External links

Basic information and pictures of Spearfish Canyon and tourism info

Geologic information and pictures of Spearfish Canyon

Information about the Scenic Byway

Black Hills National Forest (official site)
{{Authority control Landforms of Lawrence County, South Dakota Black Hills National Forest

Natural history

Flora and fauna

Geology

See also

References

External links