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Seattle, Tacoma & South Sound

Saltwater State Park: Urban Beach Escape with Washington’s Only Underwater Artificial Reef

Saltwater State Park delivers the perfect beach getaway just two miles from Interstate 5 in Des Moines, combining 1,445 feet of Puget Sound shoreline with Washington’s only underwater artificial reef for world-class scuba diving. This 137-acre park features a unique blend of sandy swimming beaches, rocky tide pools, and forested trails that wind along salmon-spawning McSorley Creek through steep ravines carved into second-growth timber. As one of Puget Sound’s most-visited state parks with 350,000 annual visitors, Saltwater State Park proves that urban accessibility doesn’t compromise natural beauty, offering everything from underwater exploration to creek-side camping in a designated Marine Protected Area.

Saltwater State Park Fast Facts

Feature Detail
Location Des Moines, King County, Washington
Address 25205 8th Place S, Des Moines, WA 98198
Size 137 acres
Coordinates 47.3758, -122.3231
Key Features Only state park with artificial underwater reef, 1,445 feet of saltwater shoreline
Activities Scuba diving, swimming, camping, hiking, tide pooling, salmon viewing
Facilities 15 campsites, picnic areas, snack shack, scuba wash station
Trail System Network of trails through ravines and along creek tributaries
Hours 8:00 AM to dusk year-round
Contact Washington State Parks Information: (360) 902-8844

Park Overview

Saltwater State Park occupies a distinctive setting where McSorley Creek has carved steep ravines through second-growth timber before reaching Puget Sound, creating diverse ecosystems within easy reach of Seattle and Tacoma. The park’s crown jewel is Washington’s only underwater artificial reef, which has transformed into a thriving marine habitat supporting sea stars, urchins, anemones, scallops, rockfish, and ling cod that can grow up to five feet long. This underwater wonderland attracts scuba divers from across the Pacific Northwest while the sandy southwest beach provides traditional beach recreation for families and casual visitors.

The creek system that defines much of the park’s character supports seasonal salmon spawning runs, adding an important ecological dimension to the recreational experience. McSorley Creek winds inland in a gentle S-curve, joined by three tributary streams that create the water features around which hiking trails and camping areas are strategically located. Despite aircraft noise from nearby SeaTac Airport’s approach pattern, the park remains one of the region’s most popular destinations due to its unique combination of marine and terrestrial recreation opportunities.

Activities & Recreation

Activity Details Season Difficulty
Scuba Diving Artificial underwater reef with diverse marine life Year-round Intermediate to Advanced
Beach Swimming Sandy beach in southwest corner of park Spring-Fall Easy
Tide Pooling Rocky tideflats exploration during low tide Year-round Easy
Creek Hiking Trails along McSorley Creek and tributaries Year-round Easy to Moderate
Salmon Viewing Seasonal spawning runs in McSorley Creek Fall Easy
Camping 15 forested campsites along bubbling creek Year-round Easy

The park’s trail network includes North Rim and South Rim trails that climb from the beach area through forests of stinging nettles, skirt cliff edges, and cross wooded plateaus before descending back to the camping area. The underwater artificial reef area is strictly protected, with fishing and harvesting prohibited to maintain the thriving marine ecosystem that has developed around the submerged structures.

Facilities & Amenities

Saltwater State Park provides comprehensive facilities for both day-use and overnight visitors. Beach amenities include a scuba wash station for divers, playground equipment, volleyball courts, and extensive picnic areas with 147 unsheltered tables available first-come, first-served plus two reservable shelters without electricity. The seasonal snack shack operates from Memorial Day weekend through Labor Day, offering fresh burgers, hot dogs, nachos, and beverages. Additional facilities include restrooms, showers, dump station, and accessible parking areas designed to accommodate the park’s high visitation levels.

Camping & Accommodations

The park offers 15 standard campsites situated along the road that parallels McSorley Creek, providing a unique creek-side camping experience within the forested ravine setting. All campsites accommodate RVs up to 50 feet in length with limited availability for longer units. Restrooms, showers, and a dump station serve the camping area. Wood fires are prohibited in the campground at any time, though propane and gas grills are permitted. All campsites operate on a first-come, first-served basis. Note that the campground area is currently closed for reevaluation and improvements following flooding and erosion impacts.

Planning Your Visit

Saltwater State Park operates year-round from 8:00 AM to dusk, requiring a Discover Pass for entry. The park’s location just two miles from Interstate 5 makes it exceptionally accessible for day trips from Seattle, Tacoma, and throughout the Puget Sound region. Visitors should check current conditions for the campground closure and any seasonal facility changes. The snack shack operates seasonally from Memorial Day weekend through Labor Day with extended weekend hours in April, May, and September. Alcohol is permitted only in designated campsites by registered campers of legal age.

What to Bring & Know

• Scuba diving gear essential for exploring Washington’s only state park artificial reef
• Tide tables helpful for optimal tide pooling and beach exploration opportunities
• Marine Protected Area designation means fishing and harvesting prohibited in reef area
• McSorley Creek seasonal salmon runs provide excellent wildlife viewing in fall months
• Aircraft noise from SeaTac Airport approach pattern affects park atmosphere
• Wood fires prohibited in campground, but propane and gas grills permitted
• Creek-side camping provides unique urban forest experience despite high visitation

Final Word

Saltwater State Park proves that urban accessibility can enhance rather than diminish natural recreation, offering Washington’s only underwater artificial reef alongside traditional beach pleasures just minutes from major population centers.

This park is part of the Explore Washington State Parks Directory—showcasing all of Washington’s State Parks from the rugged Pacific coast to the Cascade peaks. Whether you’re camping under old-growth forests, hiking scenic trails, or discovering local history, we’re highlighting the places where people connect with the state’s incredible natural and cultural heritage—all year long.

What to Do

Activities

Beach Exploration
Bird Watching
Fishing
Hiking & Walking
Kayaking
Metal Detecting
Paddleboarding
Scuba Diving
Swimming
Volunteer