U.S. Route 16A The route passes through Keystone, South Dakota; Mount Rushmore National Memorial; The Norbeck Wildlife Management Area and Black Elk Wilderness within the Black Hills National Forest; and Custer State Park (including State Game Lodge and Legion Lake); before rejoining the parent highway. US 16A is famous for its scenic, one-lane tunnels aligned to frame the faces on Mount Rushmore, its "pigtail bridges", and its sections of divided highway but with single (and narrow) lanes on each roadway. It is the only route which can be used to drive through Custer State Park without having to pay an entrance fee for
Mount Rushmore birds, including songbirds, nuthatches, and woodpeckers, inhabit the surrounding pine forests. Terrestrial mammals include the mouse, least chipmunk, red squirrel, skunk, porcupine, raccoon, beaver, badger, coyote, bighorn sheep, bobcat, elk, mule deer, yellow-bellied marmot, and American bison. The striped chorus frog, western chorus frog, and northern leopard frog also inhabit the area, along with several species of snake. Grizzly Bear Brook and Starling Basin Brook, the two streams in the memorial, support fish such as the longnose dace and the brook trout. Mountain goats are not indigenous to the region. Those living near Mount Rushmore are descendants of a tribe