How far apart are the campsite?

Depends on the loop (there are 4 of them) and which site. Most in Loops C & D are at least 5-10 feet apart with trees/shrubs between them. On Loops A & B they are mostly open bwtween them. (A & B are the " waterfront" loops)

Biking

The first come first reserved sites in d loop are mostly tent sites and private ish . Compared to RV sites along coast state parks