Desert regions above 5,000 feet may have plants blooming as late as June. More on ecology of Joshua Tree National Park Bike the Desert Dirt Joshua Tree's trails used to be the sole province of hikers, but the Park Service has seen fit to open up some of this terrain to fat-tire bike enthusiasts. The park's new Backcountry and Wilderness Management Plan designates approximately 29 miles of trails for nonmotorized bike use. Thermal Canyon Bike Trail begins at the Berdoo Canyon 4 x 4 road off of Geology Tour Road. This rigorous trail follows an old closed road through a very scenic and rugged portion of the Cottonwood Mountains with some very nice overlooks.
Overnight camping is available to visitors who register at the Pleasant Valley backcountry board.
Riding from this backcountry board adds five miles to the one-way total. The trail exits the park's south boundary at Thermal Canyon near I-10. Bird city, that's what. At spots like 49 Palms Oasis, Cottonwood Spring, and particularly Barker Dam, you might add species such as Bendire's thrasher, ladder-backed woodpecker and Scott's oriole to your life list. Many eastern vagrants accidentally end up here.