Upper & Lower Plunge trails (aka Sunnyside trail)

About

The Upper and Lower Plunge trails, collectively known as the Sunnyside trail in Aspen, Colorado, provide a difficult mountain biking experience at an elevation of 7,890 feet. The system consists of two steep sections connected by a short climb on Red Mountain Road. The Upper Plunge was rerouted in 2018 to feature grassy meadows within an aspen forest, rocky ledges, and fast turns. The lower alignment retains a rocky section that descends through dark timber forest. In 2021, the lowest portion of Lower Plunge was rerouted to avoid a rutted meadow, extending the path through aspen groves and rock gardens. The eastern bottom spur was also lengthened to connect directly to the uppermost bridge across Hunter Creek. Neither trail is recommended for uphill bike travel, making them primarily descent-focused routes. The trails are open from April through October and are dog friendly. Riders can access the Upper Plunge from 4 Corners Road or Red Mountain Road via Secret Trail. Lower Plunge is often ridden as a fast, rocky descent, frequently paired with a climb up the Hummingbird Trail to create a loop down to Hunter Valley North. The trail intersects with the Shadyside Trail and connects to the Rio Grande Trail near Roaring Fork River. Parking is available at the trailhead.