Ohio DNR is draining most of Cowan Lake for a dam rehabilitation, and the drawdown runs into 2028. The valve opens November 1 and the pool drops roughly two feet a day until it sits 13.5 feet below summer level. Work on the spillway and the dam valve system runs from early 2027 through spring 2028, and ODNR's stated target for restoring normal water levels is summer 2028. ODNR says the lake stays open for fishing and kayaking at your own risk until there is no longer enough water and the boat ramps are inaccessible. The agency has not posted a separate closure notice for the swim beach, but a 13.5-foot drop on a lake whose deepest hole is only 42 feet will leave the waterline far out from the sand. Treat the 2027 season as a write-off for swimming here, and call the park office at (937) 382-1096 before driving out. The marina is being demolished and rebuilt under the same project.

At normal pool the beach is a gradual, easy walk-in, 1,000 feet of sand on the south shore. Cowan Creek was dammed in 1950 and the lake bottom is former pasture, so expect soft silt underfoot rather than gravel or rock. Much of the lake runs 10 to 25 feet deep. Stumps were left standing when the lake was built and there are still standing trees at the upper end near the mouth of Cowan Creek, which is a good reason to stay inside the marked swim area. Swimming is permitted in daylight hours only, in designated areas, and no lifeguard is on duty. Rafts and pool toys are not allowed at Ohio state park swim areas; the only flotation permitted is a Coast Guard approved life jacket.

Getting in costs nothing. Ohio charges no admission at any of its state parks and no fee to use a state park beach. A changing house and restrooms sit at the beach, and the beach lot has marked accessible spaces. The beach is carry in, carry out with no trash cans, so bring a bag. Alcohol is prohibited in public areas of every Ohio state park, the beach included. The Ohio Department of Health posts water quality advisories for this beach through BeachGuard from Memorial Day to Labor Day.

The lake's calling card is its American lotus. The shallow bays hold an unusually large colony for an inland Ohio lake, with leaves up to two feet across and big yellow flowers through midsummer. Bald eagles work the shoreline. A 10-horsepower limit keeps all 692 acres quiet, which is why sailing took hold here. Three ramps and an accessible kayak launch ring the water, South Shore Marina rents boats and canoes, and the campground commissary rents kayaks and paddleboards seasonally. A second, smaller beach serves the campground, and there is a boat swim area in the northern arm of the lake.

The campground carries a wide mix of sites plus fully equipped cabins, a seasonal nature center, and a group camp. More than eight miles of trail cross the park, including the 2.6-mile Spillway trail and the 1.8-mile Emerald Woods loop on the south side near the beach, and an 18-hole disc golf course sits by the Dance Pavilion a short walk from the sand. An accessible fishing pier is near the Pine Tree picnic area. The park is seven miles southwest of Wilmington, reached from U.S. 68 or State Routes 350 and 730, with the beach off Yankee Road.