http://www.nps.gov/caha/index.htm
Here is information on camping:
http://www.nps.gov/caha/planyourvisit/campgrounds.htm
Need a beach permit? You can get one at the NPS Visitors’ Center located near the Swan Quarter/Cedar Island ferry docks:
http://www.nps.gov/caha/planyourvisit/off-road-vehicle-use.htm