The Potholes are the defining geologic feature near this eastern Washington park. A series of Ice Age flood-carved depressions in the earth, combined with the dynamics of the O’Sullivan Dam, created hundreds of tiny islands surrounded by “pothole” lakes.

These little lakes make up half the O’Sullivan Reservoir, and Potholes State Park lies on the other side, where visitors find the lakes deeper and welcoming to boaters, fishers and swimmers.

The year-round fishing at Potholes is superb, with abundant yellow perch, crappie, largemouth bass, rainbow trout and walleye. But if you would rather be in the water on a hot, eastern Washington day, swimming and water sports abound. Think waterskiing, kayaking and paddleboarding.

More into birding than fishing? Fill your field journal on a visit to the Potholes lakes and islands. Sandhill cranes and waterfowl come through in late February; raptors in April; sage thrasher, lark sparrow and burrowing and long-eared owls arrive in May, along with shorebirds. When water levels drop in August, the mud flats beckon sandpipers, stilts, plovers and curlews.

If you have a sleeping bag, eastern Washington is the place to sleep under the stars, or you can rent a cute cabin in the primitive campground. Either way, you’ll have fun and learn about natural history and geology at this fascinating park.

PARK FEATURES
Potholes State Park is a 773-acre camping park with 6,000 feet of freshwater shoreline on O'Sullivan Reservoir. This body of water is often confused with the Pothole Lakes themselves, which are a 30- to 45-minute drive from the park. The terrain is desert with freshwater marshes.

ADA AMENITIES/FACILITIES

Campground
Restroom

PICNIC & DAY-USE FACILITIES
The park provides three picnic shelters with four tables each, plus 73 unsheltered picnic tables in a lawned, well-shaded area. All day-use facilities are first come, first served. Restrooms are available in the day-use area, located on the banks of the reservoir.

ACTIVITIES

TRAILS
3 miles of hiking trails

WATER ACTIVITIES & FEATURES
60 feet of dock
Boating
Fishing (freshwater)
Fish cleaning station
Personal watercraft use
Swimming
Watercraft launches (4)
Waterskiing
White-water kayaking

OTHER ACTIVITIES & FEATURES
Bird watching
Horseshoe pit
Volleyball fields (2)
Wildlife viewing

BOATING FEATURES
Located in Grant County on Potholes Reservoir, the park offers four watercraft launches and 60 feet of dock. Water levels in O'Sullivan Reservoir (Potholes Reservoir) fluctuate dramatically from spring to fall.

Launching a boat at a state park requires one of the following:

An annual launch permit (Natural Investment Permit); or
An annual Discover Pass and a daily launch permit; or
A one-day Discover Pass and a daily launch permit.

CAMPSITE INFORMATION
The park has 61 standard campsites, 60 full-hookup sites, five cabins, one dump station, four restrooms (two ADA), and four showers (two ADA).

Any tent or RV may use either site type. But, anyone using the full-hookup sites will pay that site fee. Maximum site length is 50 feet (limited availability). There is no camping next to the reservoir.

Check-in time is 2:30 p.m.
Check-out time is 1 p.m.