Griffiths-Priday Ocean State Park is a 364-acre marine park with 8,316 feet of saltwater shoreline on the Pacific Ocean and 9,950 feet of freshwater shoreline on the Copalis River. The park extends from the beach through low dunes to the river, then north to the river's mouth. The Copalis Spit natural area, a designated wildlife refuge, is also part of the park.

The park owes its existence to Judge Griffiths, who in the late 1800s purchased the original 117 acres that he willed at his death to be made into a park for everyone's enjoyment. Griffiths stipulated that the park be named Griffiths-Priday Ocean State Park, a combination of his surname and the name of his foster parents who brought him to America from England as a child.

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 no camping.