Birch Bay State Park is a 664-acre camping park with 8,255 feet of saltwater shoreline on Birch Bay and 14,923 feet of freshwater shoreline on Terrell Creek. The park is rich in archeological significance and offers panoramic views of the Cascade Mountains and Canadian Gulf Islands. The Terrell Creek Marsh is one of the few remaining saltwater/freshwater estuaries in north Puget Sound. The park features nearly two miles of beach and great views of the Canadian Gulf Islands and the Cascade Mountains. A natural game sanctuary is at the park's north end.

Birch Bay was named by botanist Archibald Menzies for its abundance of black birch trees. Menzies was on the 1792 Vancouver expedition. Archeological evidence indicates that the bay was inhabited by Semiahmoo, Lummi and Nooksack tribes since prehistoric times. At the turn of the 20th century, the huge fir trees of the area were logged with oxen and horse teams. Large old-growth stumps, with spring-board marks, remain as evidence.

A Discover Pass is required for vehicle access to Washington state parks for day use. For more information about the Discover Pass and exemptions, please visit the Discover Pass web page.

The park has tent spaces 12' x 12' in the forested camping area, plus utility spaces, an RV dump station, eight restrooms, and showers two ADA. Camping areas are subject to availability, and reservations are accepted for summer camping.