The state park's 1,064 acres (431 ha) include both freshwater and saltwater shorelines.

The park offers opportunities for picnicking, camping, hiking, boating, fishing, swimming, scuba diving, and shellfish harvesting.

The park's flats were the site of several old homesteads in an area known as Dose Meadows.

The railroad beds found in the park's far southeast side are leftover from the days when timber was hauled by rail from the mountains to be deposited in the water and floated off to ships and mills.

[3] Four species of wild salmon and steelhead use the Dosewallips River for spawning, and the park provides wintering grounds for a herd of elk.