- Birch Bay State Park is a 225.1-acre (91.1 ha) Washington state park located nine miles (14 km) south of Blaine in Whatcom County, within the town of Birch Bay. The park has 7,915 feet (2,412 m) of saltwater shoreline on Birch Bay and 15,000 feet (4,600 m) of freshwater shoreline along Terrell Creek. Recreational opportunities include camping, picnicking, fishing, hiking, crabbing, clamming, and boating.