Alder Backcountry Trail Camp is a basic six-site camp along the Skyline to the Sea Trail inside Big Basin Redwoods State Park. Geared toward backpackers along the trail, the campground has a vault toilet, trash can, and bear lockers. Of the six sites, none are particularly scenic; however site 2 is set above a creek, which can provide a nice ambiance. Site 6 is the most secluded and requires a short walk down a path to reach. All sites have a flat area that is meant for a tent.
Horses are not allowed at Alder Camp. The camp is located 1.6 miles from Highway 1, and it can fill up during summer weekends when park hiking traffic is at its peak. Reservations are required, and they are handled through the California State Parks Department. More information on the reservation process and site guidelines can be found here. Camp fees are $15 nightly. The more scenic Twin Redwoods Backcountry Trail Camp is located about a half-mile further up the Skyline to the Sea Trail and may also be worth looking into.