South Twin Day Use Area

The lake was formed about 20,000 years ago when rising magma-encountered groundwater resulting in violent steam explosions. The resulting explosions formed a broad shallow crater, which later filled with water.

This site is a popular swimming and picnicking area in the summer months. There is a boat ramp here for non-motorized boats. 

Recreation Fee Site: Parking at this site requires a recreation pass May 1 – September 30. Passes are available at this site, but can also be purchased from Forest Service offices or vendors. Please check here for more information about recreation passes and where they can be purchased.

Acceptable passes include:

• $5 Day Pass
• Northwest Forest Pass
• Interagency Annual Pass
• Interagency Senior Pass (America the Beautiful, Golden Age)
• Interagency Access Pass
• Interagency Military Pass
• Every Kid in a Park Pass
• Northwest Forest ePass