Fairholm Campground ($12; open year-round), on the west end of Lake Crescent [1], has summertime naturalist programs on some evenings. The Forest Service’s Klahowya Campground (nine miles west of Lake Crescent on Hwy. 101, $12) opens sites May to mid-October.
Park RVs along Lake Sutherland at Shadow Mt. RV Park (360/928-3043).
Fairholm General Store (360/928-3020) on the west end of Lake Crescent, is open April–September, and has tent sites and RV hookups, plus motorboats, rowboats, and canoes for rent. It also serves meals in the café; eat alfresco on a deck overlooking the lake.
Links:
[1] http://www.moon.com/destinations/washington/olympic-peninsula-and-the-coast/port-angeles-sol-duc/lake-crescent