Vandalia Lake Beach, which the City of Vandalia calls Jaycees Beach, is the public swimming area on Vandalia Lake, a 660-acre reservoir in Fayette County, Illinois. The city owns the lake for water supply and flood control and runs the beach together with a marina, boat launch, campground and picnic grounds on the south shore. The lake was built in 1967 on Bear Creek, a tributary of the Kaskaskia River, and its 12 miles of shoreline are lined with wooded coves and lake homes.

The lake sits about four to five miles northwest of downtown Vandalia along Illinois Route 185. Follow 185 out of town and turn north onto the county roads that lead to the city lake grounds (County Road 1875 North serves the campground and marina). The beach is on a small point on the south shore, west of the marina and boat ramp. There is parking in the lake grounds, and the campground, pavilions and playground are all close by. Much of the rest of the shoreline is private lots and leased camping lots, so use the city area rather than looking for another way to the water.

The swim area is a wide sand beach that slopes gradually into the lake, which is the kind of entry families with small children look for. Vandalia Lake is a warm, fairly turbid prairie reservoir: an Illinois Natural History Survey sheet posted by the city puts its average depth around 10 feet and its deepest water near 31 feet, and measured water clarity at under three feet. By midsummer the water is warm enough for long swims. There is no current to speak of, but the bottom drops off as you move away from shore, and the city says plainly that there are no lifeguards. Swimming is at your own risk.

The city lists the beach season as Memorial Day weekend through Labor Day, open daily, holidays included, from 10 a.m. to 6 p.m., weather permitting. The city's own page lists the swim fee as no charge, so the beach is free. An older chamber of commerce listing still shows a small swim fee and a lifeguard, so if the season dates or fee matter to your plans, call the lake office at (618) 283-4770 or City Hall at (618) 283-1196. Camping costs extra, with nightly rates for electric and full-hookup sites set by the city.

Know about two things before you go. Vandalia Lake is a busy boating, tubing and jet-ski lake, so stay inside the swim area and watch for wakes. The Illinois Department of Public Health monitors this beach under its BeachGuard program, which tests for bacteria and posts advisories or closures when results run high, so check the BeachGuard page before a summer visit, especially after heavy rain. Restroom and concession service at the beach house can change from season to season, so bring water and snacks of your own.

Beyond swimming, the lake grounds have shaded picnic tables, large pavilions you can reserve through City Hall, playground equipment near the beach and the Lions pavilion, volleyball, horseshoe pits, concrete cornhole boards and a kayak launch. Anglers fish for largemouth bass, channel catfish, crappie and bluegill, and boaters need a city lake permit. The historic Vandalia Statehouse, where Abraham Lincoln served as a young legislator, is a short drive back into town.