ADAMS LAKE PRAIRIE STATE NATURE PRESERVE - 26 ACRES Main Feature: Cedar barren prairie; good summer wildflowers and butterflies. Location: Located in Adams County within Adams Lake State Park, which is 1 mile north of West Union on State Route 41. The marked entrance to the preserve is at the far west end of the park road. A trail system with trail-side interpretive signs is present. Other visitor facilities including restrooms, drinking water and picnicking are available in the adjacent state park. Adams Lake State Park 14633 State 41 West Union, Ohio 45693 (740) 858-6652 47 acre limited horsepower lake. Only non-powered craft and those with electric motors permitted on the lake. A small launch ramp near the park entrance provides access to the 47-acre lake