Mongold Day-Use Area is a state park site on the north shore of Detroit Lake in Oregon along Oregon Route 22, about 3.5 miles west of Detroit. Though it lies about 1.5 miles beyond the boundary of Detroit Lake State Park, the Oregon Parks and Recreation Department administers it as part of that larger park. Designed for short visits rather than overnight stays, it offers a boat ramp, swimming area, fishing access, and picnic area. The site’s significance lies in providing convenient day access to Detroit Lake and the surrounding recreation area.