Cycling allowed on many trails and all fire roads. From Highway 1 in Aptos, take the State Park Road exit to the north. Drive under a railroad bridge then look for Aptos Creek Road on the left. The sign is small, so pay attention. There is a parking area right after the turn on Aptos Creek Road.
Bicyclists tend to park at the free lot.
There are trails connecting Portola to Castle Rock, Sanborn Canyon, and Big Basin. Portola is often empty - you can get the whole canyon to yourself on weekdays. Main campground has restrooms, hot showers, and mosquitoes - each campsite has a table and stove. Activities Hiking, Camping, Backpacking. Dogs not allowed on trails.