The Buffalo Gap National Grassland lies is southwestern South Dakota, virtually surrounding Badlands National Park, then reaching west into the rain shadow of the Black Hills, nearly to the hogback. One of the original 19 national grasslands, this 595,000 acre public prairie is the nation's second largest national grassland…Parts of the Buffalo Gap border both the states of Nebraska and Wyoming and the Pine Ridge Indian Reservation in South Dakota.

The grassland is divided into two ranger districts: the Wall Ranger District, with offices in Wall on the east, and the Fall River Ranger District, with offices in Hot Springs on the west.

Recreation is also big demand on the Buffalo Gap. Hiking into such remote road less areas as Red Shirt and Indian Creek is growing in popularity…The many agate beds, such as the Kadoka and Fairburn beds attract rock hounds, and the beds include such gems as prairie agates, jasper, red carnelian, moss agate, blue chalcedony, puddingstone conglomerate, and the South Dakota's state gem, the highly collectible and colorful Fairburn agate.

A veritable treasury of fossils is found on the Buffalo Gap. In fact, fossil resources from the Oligocene (30 to 40 million years ago) and the Eocene Epoch (32 to 37 million years ago) are some of the richest to be found anywhere in the world and are revealed in the clays eroding from the color-banded buttes and cutbanks. Oligocene and Eocene fossils include prehistoric horses and camels, titanotheres (similar in size to the rhinoceros), pigs and saber-toothed cats. Marine fossils from an even earlier time - the Late Cretaceous age, some 65 to 80 million years ago - also turn up, and include ammonites, mosasaurs, sea turtles and the Loch Ness-like plesiosaur, a ferocious-looking reptile as long as a bus.