Nestled in the northern portion of the Black Hills National Forest, Big Hill Trails is a 15-mile network of hiking and biking routes. The network derived its name during the Gold Rush of the late 1800s, when gold prospectors struggled to get their horses and wagons over what they dubbed the "big hill" from Spearfish. Located just seven miles south of Spearfish, the trails loop through densely wooded terrain above the scenic Spearfish Canyon, affording breathtaking views of deep gorges and soaring cliffs. This is a relatively quiet region of the Black Hills, with less tourist activity than the more congested Centennial Trail and George S. Mickelson Trail.

The surfaces of the Big Hill Trails are generally well-maintained and conducive to leisurely riding. Skill levels range from easy to moderately challenging, some with long, steady climbs and descents at elevations ranging from 5,000 to 5,520. The diverse natural surroundings range from aspen-forested ridges to open meadow areas. In winter months, the trails are maintained by the Northern Hills Cross Country Ski Club; donation boxes are posted at the trailheads.

• Loop A: This easy trail is 2.1 miles, and meanders through aspen, birch, and ponderosa pine forests.
• Loop A.1: This easy ½-mile trail runs through aspen, birch, and ponderosa forests.
• Loop B: This moderate, 2.4-mile trail offers a more challenging ride against a wooded backdrop of aspen, birch, and ponderosa pine. Bikers will encounter roots, rocks, sharp switchbacks, and steep inclines.
• Loop C: This moderately difficult trail meanders for 5.5 miles. Bikers will encounter some loose rocks and relatively steep inclines and descents.
• Loop C.1: This easy, 1.5-mile trail overlooks the west rim of Spearfish Canyon.
• Loop D: This heavily wooded, 4.5-mile trail is moderately challenging, although most of it has been converted to a two-track road.