South Dakota Highway 87 (SD 87) is a 37.894-mile-long (60.984 km) state highway in the southwestern part of the U.S. state of South Dakota. It travels through the Black Hills region. The highway's southern terminus is at an intersection with U.S. Route 385 (US 385), about 6 miles (9.7 km) southeast of Pringle, within the southwestern part of Wind Cave National Park. Its northern terminus is at an intersection with US 16/US 385 about 3 miles (4.8 km) south-southwest of Hill City, within the east-central part of the Black Hills National Forest.
The highway travels through Wind Cave National Park. The northern 14 miles (23 km) of the highway is also known as the Needles Highway. The Needles Highway, along with the concurrency with US 16A, are also part of the Peter Norbeck Scenic Byway. Portions of the highway are also a section of Custer State Park's Wildlife Loop.