DamTour 2011:    


marker 6 ~ O'Sullivan Dam ~ WA ~  284 mi from PDX - 186 mi Sea-Tac.

O'Sullivan Dam, is one of the largest zoned earth fill dams in the entire United States, and creates Potholes Reservoir. It is on Crab Creek about 15 miles south of Moses Lake. The dam forms the 27,800-acre Potholes Reservoir which collects return flows from all irrigation in the upper portion of the project for reuse in the southern portion. Off Hwy 17, take Hwy 262 (O'Sullivan Dam Road) and you're there.

Potholes State Park, on the east side of the reservoir near the dam.

** Thanks to Jim Carroll for scouting and photos.

    GPS:   46.97652°N - 119.30290°W    or    46 ° 58' 35" N - 119° 18' 10 " W

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    Elevation : 1054 feet

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  • O'Sullivan Dam photos by Jim Carroll
  • O'Sullivan Dam photos by Jim Carroll
  • O'Sullivan Aerial
  • Satellite Image
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Potholes State Park

Bureau of Rec -O'Sullivan Dam

Moses Lake, WA

Milwaukee Caboose

Rider Photos

O'Sullivan Dam Riders