Big Thunder Lake Public Water Access Site features a concrete boat ramp administered by the Minnesota DNR, providing access to a 1,347-acre lake with 16 miles of shoreline.

The ramp is located on the west side of Thunder Lake in Cass County and is typically open 24 hours a day with no launch fees.

The site is designed for launching watercraft up to 18 feet in length and is suitable for both motorboats and paddling enthusiasts exploring this clear-water lake.