Wyoming’s high mountain lakes are famously cold, but its sunny prairie and foothill reservoirs warm up nicely in summer – with sandy beaches that are a surprise to many visitors. This guide rounds up the best swimming lakes in Wyoming, focusing on the reservoirs with real beaches and warmer water. Each links to our full lake guide. This page is part of our Wyoming Lakes Database.
The best swimming lakes in Wyoming
- Glendo Reservoir. Famous for its sandy beaches and warm water, Glendo State Park is arguably Wyoming’s top swimming-and-boating lake, hugely popular on summer weekends.
- Guernsey Reservoir. Guernsey State Park has sandy beaches and warm, calm water in a scenic setting, a longtime family swimming favorite in southeast Wyoming.
- Alcova Reservoir. Casper’s summer playground, Alcova has beaches, marinas and warm North Platte water for swimming and boating.
- Keyhole Reservoir. A warm prairie reservoir near Devils Tower with beaches and a state park, good for swimming and walleye fishing.
- Boysen Reservoir. Boysen State Park, at the mouth of Wind River Canyon, has beaches and warm, open water for a summer swim.
- Bighorn Lake. In Bighorn Canyon National Recreation Area, this scenic reservoir offers swimming and boating in dramatic canyon country.
Tips for swimming in Wyoming lakes
For swimming, skip the cold, high alpine lakes and head to the lower-elevation reservoirs – Glendo, Guernsey, Alcova, Keyhole and Boysen – where the water warms through summer and state parks provide sandy beaches, restrooms and picnic areas. Beaches are generally unguarded, and Wyoming’s reservoirs can be windy and develop chop and drop-offs, so swim with care. Reservoir levels also drop through the irrigation season, which can change the beaches.
Frequently asked questions
What is the best swimming lake in Wyoming?
Glendo Reservoir, with its sandy beaches and warm water at Glendo State Park, is widely considered Wyoming’s best swimming lake; Guernsey Reservoir is another top family beach.
Are Wyoming lakes warm enough to swim?
The high mountain lakes stay cold, but lower-elevation reservoirs like Glendo, Guernsey, Alcova, Keyhole and Boysen warm up nicely for summer swimming.
Which Wyoming state parks have swimming beaches?
Glendo, Guernsey, Boysen and Keyhole state parks all have sandy swimming beaches, and Alcova Reservoir near Casper has beaches as well.
Related: see the largest lakes in Wyoming, the best lakes in Wyoming, or head back to the Wyoming Lakes Database.
