Big Flat Lake   Be the first to submit input for Big Flat Lake. If you have info on Big Flat Lake, Clinton County, Illinois please submit it here to improve this web site.          These outdoors activities are available near Big Flat Lake.   Lakes Near Big Flat Lake: Carlyle Reservoir, Clinton County, 9 miles away   Marinas On or Near Big Flat Lake: Tradewinds Marina, Keyesport, 18 miles away Boulder Access Marina, Shattuc, 19 miles away   Camp Grounds Near Big Flat Lake: Carlyle Lake, Carlyle, 9 miles away Boulder Campground, Carlyle, 9 miles away Coles Creek Campground, Carlyle, 9 miles away   Hotels Near Big Flat Lake: Super 8 Okawville, Okawville, 7 miles away Best Western U. S. Inn, Nashville, 8 miles away Super 8 Carlyle, Carlyle, 9 miles away Timmermann House Bed & Breakfa, Aviston, 12 miles away Sleep Inn & Suites Greenville, Greenville, 21 miles away   Ski Areas Near Big Flat Lake: Hidden Valley, Missouri, 83 miles away       250 foot drop, 6 lifts, 9 runs