William O'Brien State Park

The highway that used to run through the park has been permanently closed. There is now an unavoidable 16 to 20 mile drive to get from Yellow Medicine Campground on the east side to the park office, main entrance or horse campground on the west side. Be aware that Google Maps and most other map and GPS apps are still routing people down the closed highway to get between the park office and the campgrounds. This will not work!  Use these directions and coordinates in your GPS instead to get to the horse campground, the backpack/watercraft campground, or the Yellow Medicine River Campground. (Campers, please go directly to your site - park staff will come around to check you in.)