Twanoh State Park is a public state park in Washington near Union in Mason County. Spanning 182 acres and established in 1923, this park offers a peaceful retreat into nature for visitors of all ages.
Quick Facts
| State | Washington |
| Nearest City | Union |
| County | Mason |
| Park Size | 182 acres |
| Established | 1923 |
| Google Rating | ⭐ 4.5/5 (800 reviews) |
| Accessibility |
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Location & Getting There
Twanoh State Park is located near Union, Washington. The park’s coordinates are 47.4569, -123.0042.
Things to Do
Washington state parks offer an incredible diversity of outdoor recreation — from the rain-soaked old-growth forests of the Olympic Peninsula to the volcanic landscapes of the Cascades, the arid canyonlands of Eastern Washington, and the island-dotted waters of Puget Sound. Popular activities include hiking through moss-draped temperate rainforests, beachcombing on wild Pacific shores, kayaking through the San Juan Islands, camping beneath towering Douglas firs, fishing for salmon and steelhead in glacier-fed rivers, rock climbing basalt columns, mountain biking forested trails, and cross-country skiing in winter. Many parks also offer historical interpretation, including military forts, pioneer homesteads, and Native American cultural sites.
Best Time to Visit
Washington’s outdoor season varies dramatically by region. Western Washington (including the coast and Puget Sound parks) is driest and warmest from June through September — this is peak season. Spring and fall bring fewer crowds and mild temperatures but expect rain. Eastern Washington parks enjoy more sunshine year-round, with hot summers and cold, snowy winters. The San Juan Islands are best visited May through September for whale watching (orcas) and calm seas. Mountain parks in the Cascades open as snow melts, typically July through October. Winter transforms many parks into cross-country skiing and snowshoeing destinations. Always carry rain gear west of the Cascades, regardless of season.
Visitor Tips
Washington state parks require a Discover Pass ($30/year or $10/day) for vehicle access. Purchase one online through the Washington State Parks website before your visit — it covers all 100+ state parks. Camping reservations are made through the state parks reservation system up to 9 months in advance. Popular parks like Deception Pass and Cape Disappointment book months ahead for summer weekends. Many parks in the San Juans and islands are accessible only by ferry or boat — check Washington State Ferries schedules in advance. Cell service can be unreliable, especially on the coast and in mountain parks.
Frequently Asked Questions
What is a Washington Discover Pass?
The Discover Pass ($30/year or $10/day) is required for vehicle access to all Washington state parks and recreation lands. It can be purchased online, at park entrance stations, or at licensed vendors.
What is the most visited state park in Washington?
Deception Pass State Park on Whidbey Island is the most visited state park in Washington, famous for its dramatic bridge spanning the narrow gorge and stunning views of Puget Sound and the San Juan Islands.
Can I camp on the San Juan Islands?
Yes, several San Juan Islands parks offer camping, including Moran State Park on Orcas Island and Spencer Spit on Lopez Island. Accessible only by Washington State Ferries — book ferry reservations early in summer.
What is the best time to visit Washington state parks?
June through September offers the driest conditions west of the Cascades. The coast can be enjoyed year-round (winter storm watching is popular). Always carry rain gear when visiting parks west of the Cascades.
Explore More Washington State Parks
Twanoh State Park is one of many outstanding state parks in Washington. Discover more parks in our Best State Parks in Washington guide, or use our Park Finder to search by activity, location, or features.
Wildlife & Nature
Twanoh State Park — 182 acres on Hood Canal in Mason County — offers one of the warmest saltwater swimming beaches on the canal, with water temperatures reaching 70°F+ in summer — unusual for Puget Sound waters. The park was built by the Civilian Conservation Corps (CCC) in the 1930s — original stone and log structures remain. Harbor seals swim in the canal. Bald eagles fish from shoreline conifers. The park offers shellfish harvesting (oysters, clams). Great blue herons stalk the shallows.
Nearby Attractions
Belfair State Park — 5 miles east — has additional Hood Canal beach access. Kitsap Memorial State Park — 15 miles north — has Olympic Mountain views. Potlatch State Park — 10 miles south — sits on ancestral Skokomish lands. Shelton — 20 miles south — provides services.
Keep exploring: The closest neighbors are Lilliwaup Tidelands State Park (a short drive away) and Belfair State Park (a short drive away).
🐾 Dogs & Pets at Twanoh State Park
- Pets allowed? statewide rule
- Pets are allowed in most Washington state parks but must be under physical control on a leash at all times.
- Leash rule statewide rule
- 8 ft maximum leash required; pets must be under physical control
- Beaches & swim areas statewide rule
- Pets are not permitted on designated swim beaches
- Cabins & lodging statewide rule
- Pets are not allowed inside vacation houses but are permitted in designated pet-friendly cabins and yurts (e.g. Cape Disappointment, Grayland Beach, Seaquest, Ike Kinswa), typically up to two pets, with a pet fee
- Pet fees statewide rule
- No day-use pet fee; $15 per night pet fee in pet-friendly cabins/yurts
- Statewide exceptions statewide rule
- Director-designated off-leash areas are exempt from the leash rule and are conspicuously posted
Are dogs allowed at Twanoh State Park?
Pets are allowed in most Washington state parks but must be under physical control on a leash at all times. Individual parks can post stricter rules — check signage on arrival.
Rules verified July 2026 via parks.wa.gov. More: Washington state parks guide · Dog rules in all 50 states compared
Park Location
Plan your gear for Twanoh State Park
From our editorial guides, matched to this park’s activities:
