Seaquest State Park is a public recreation area located on the western flank of Silver Lake in Cowlitz County, Washington. The 505 acre state park is home to the Mount St. Helens Visitor Center, which offers displays on the Mount St. Helens volcanic eruption of 1980. Mount St. Helens itself is 30 mi east of the park.

Activities and amenities

Park activities include camping, 7 mi of hiking trails (including 1 mi of ADA-accessible trail), picnicking, bird watching, and horseshoes. The park has a mile-long shoreline on Silver Lake, a shallow lowland lake with wetlands trail and boardwalk, boat launch, and fishing. The Mt. St. Helens Visitor Center opened in 1986 and was originally managed by the United States Forest Service (USFS) and operated, under permit, by the Washington State Park system until 2007, when the center was fully transferred to the state. Approximately 300,000 visitors were recorded that year. The 16,000 sqft space underwent its first upgrade in 2024, which included artworks, displays, and exhibits expanding on the history and connection of the Cowlitz Indian Tribe to the mountain and surrounding lands.