The main boat ramp at Lake Thompson Recreation Area near De Smet provides access to one of South Dakota's largest natural lakes with over 44 miles of shoreline.

The ramp underwent complete replacement in fall 2024 (closed October 2 for approximately 4-6 weeks), and alternative access points are available at the Lake Thompson Lakeside Use Area on the northwest side and Lake Thompson Southwest (Jerry's Access) Public Water Access during maintenance.

The recreation area offers 97 campsites with electrical hookups, a dump station, fish cleaning station, and various amenities for both boating and fishing enthusiasts.