Gun Lake Beach is the public swimming beach in the Gun Lake day-use area of Yankee Springs Recreation Area, a 5,200-acre state recreation area managed by the Michigan Department of Natural Resources in Yankee Springs Township, Barry County. The park takes in the east side of Gun Lake, a 2,680-acre lake that reaches into Allegan County at its southwest tip. Most of the rest of the shoreline is cottages and private homes, so the state land is one of the few places on the lake where anyone can walk to the water and swim. The sand beach lies on the east shore just south of the park's 200-site modern campground, with the beach house set back behind it.

The park office is at 2104 S. Briggs Road, Middleville, about 12 km south-southwest of the village of Middleville. The day-use area has paved parking lots, restrooms and open lawn between the lots and the water.

The DNR keeps buoyed swim areas in the Gun Lake day-use area, and the buoys are normally in from Memorial Day weekend through Labor Day. Once they come out, the shoreline is no longer a designated swim area. Michigan state parks do not post lifeguards, so swimming here is at your own risk, and the DNR asks swimmers to stay inside the buoys, never swim alone and keep children within reach. The bottom along the beach is sand, but Gun Lake reaches about 66 feet at its deepest and is a busy boating lake, so the buoy line matters. A beach wheelchair is available, and the park lends a track chair at no cost. Pets are allowed along the park's lakes but not on the designated swim beaches. Alcohol is banned in the Gun Lake day-use area from April 1 through Labor Day.

Entry is not free. Every vehicle needs a Michigan Recreation Passport. For Michigan-registered cars the passport is annual only, $15 when added at license plate renewal through the Secretary of State, with a $5 convenience fee if bought any other way. Out-of-state vehicles pay $12 for a day pass, good for entry and re-entry to any state park that day, or $42 for the year. Daily passes are sold at the park. Hours are not posted on the park page, so call the park office at 269-795-9081 if you plan an early or late swim.

Beach water testing in Michigan is voluntary and done by local health departments, which post results to EGLE's BeachGuard system. Look there for advisories before you go, particularly after heavy rain.

The beach house holds restrooms, paddlesport rentals and Yankee Bill's, a concession that sells hot food, ice, firewood and camping supplies. Picnic tables and charcoal grills are first come, first served, and two pavilions can be reserved through MiDNRReservations.com. Beyond the beach, the park has about 30 miles of hiking and cross-country ski trails, 12 miles of mountain bike trail, a stretch of the North Country Trail, the Devil's Soupbowl kettle and the Graves Hill overlook, plus a rustic campground on Deep Lake and several smaller lakes for fishing and paddling.