Southeast of Twin Falls and south of Hansen in the Rock Creek Recreation Area, the South Hills has a huge trail network open to mountain biking.
To reach the Third Fork Trailhead from the intersection of US 30 and CR G3 (Rock Creek Rd.) in Hansen, go south on CR G3 for 21 miles. Park on the left at the Third Fork Trailhead.
Overall, Third Fork / Heart Attack Loop is the 57th most popular mountain bike trail of all 63 mountain biking rides in Idaho.