Guernsey Dam, Dam and hydroelectric power station in Platte County, Wyoming, United States

Guernsey Dam is an earthfill dam on the North Platte River in Platte County, Wyoming, creating Guernsey Reservoir. The dam includes a hydroelectric power station with a capacity of 6.4 megawatts, and the reservoir stores water mainly for irrigation.

Guernsey Dam was built in the 1920s as part of the North Platte Project to provide irrigation water to eastern Wyoming and western Nebraska. It was constructed by Morrison-Knudsen and the Utah Construction Company, and it helps control the river's flow and store water released from Pathfinder Reservoir upstream.

The reservoir and dam are part of Guernsey State Park, where local families come to fish, swim, and camp. The park's trails and picnic spots offer a chance to see how people in this region spend their weekends outdoors.

The dam is best visited from late spring through early fall, when the surrounding state park is fully open and the weather is mild. Access to the dam and power station is mostly by car, and some areas may require a short walk on uneven ground, so wear sturdy shoes.

The dam's power station can be visited on a guided tour, offering a look at how hydroelectricity is generated. The Historic American Engineering Record No. WY-94 documents the dam with 25 photos and several pages of data, preserving its engineering details for researchers.