Unified Interior Regions

Spearfish Creek in the northern Black Hills of South Dakota.

Headwater springflow is common in the Limestone Pateau area in the Black Hills of western South Dakota. Most headwater springs in the Black Hills, like this one contributing to Rhoads Fork, generally occur near the base of the Madison Limestone along the eastern edge of the Limestone Plateau area.

Photograph taken in 2001 of Mt. Coolidge area in Black Hills of western South Dakota. The area was burned by the Galena Fire in 1988, which burned approximately 17,000 acres in Custer State Park.

Bear Butte Creek in northern Black Hills near Deadwood, SD.

Towering cliff of the Deadwood Formation in Deadwood, SD. The Deadwood Formation consists mostly of sandstone and shale.

Grace Collidge Creek above loss zone in southern Black Hills of South Dakota.

Spearfish Formation near Spearfish, SD. The Spearfish Formation is a red, silty shale with interbedded red sandstone and siltstone. The formation contains massive gypsum deposits, which is the white layer in the photograph.

Naturally occuring bog-iron area near Rochford, SD, in the Black Hills of western South Dakota.

Photograph taken in 2001 of an area burned by the Jasper Fire that started on August 24, 2000, just west of Jewel Cave in the southern Black Hills of South Dakota. A total of about 84,000 acres was burned by the Jasper Fire.

Outcrop of the Madison Limestone in Spearfish Canyon in the northern Black Hills of South Dakota. The Madison Limestone is a massive, gray to buff limestone with some dolomite.

Outcrop of the Minneslua Formation at Ranch A near Beulah, Wyoming. The Minnelusa Formation consists mostly of yellow to red sandstone, limestone, dolomite, and shale.