Spearfish Canyon, Canyon in Lawrence County, South Dakota.

Spearfish Canyon is a deep, narrow gorge carved by Spearfish Creek in the Black Hills of Lawrence County, South Dakota. Its walls expose three rock layers: brown Deadwood Shale at the base, pink to red Englewood Limestone in the middle, and buff to gray Paha Sapa Limestone on top. US Route 14A, the Spearfish Canyon Scenic Byway, follows the creek through the gorge.

Spearfish Canyon was carved by Spearfish Creek through Precambrian rock, with the upper walls made of Paha Sapa Limestone, the middle of pink to red Englewood Limestone, and the base of brown Deadwood Shale. The canyon lies within the Black Hills, and its current form developed over millions of years. The highway through it follows a railroad grade abandoned after massive flooding in 1933.

The canyon takes its name from Spearfish Creek, the stream that carved the gorge and runs its full length. The creek also gives its name to the town of Spearfish at the canyon's north entrance. The scenic byway follows the old railroad grade abandoned after the 1933 flood.

The best time to visit is May through October, when the road is fully open and hiking trails are easily accessible. Winter weather can make conditions challenging with snow and ice, so check forecasts and plan accordingly.

The Pahasapa, or Black Hills mountain snail, is a small land snail found only in the Black Hills, including Spearfish Canyon. It is rare and declining because of habitat degradation, so look for it in damp, shaded spots rather than along the road.