Accessible only by boat, Clark Island Marine State Park is a 55-acre marine camping and moorage park with 11,292 feet of saltwater shoreline on the Strait of Georgia. Boaters anchoring offshore or using the park moorage buoys should be aware of the strong currents on the west side of the island. The east side moorage area is subject to large waves created by passing commercial shipping in Rosario Strait.

Bug repellent is recommended into September, particularly for those using the more shaded camp spots. Cellular phone service is often available here, as Clark Island is close to a cell tower on Orcas.