Mary Jane Thurston State Park is a 105-acre public recreation area on the Maumee River west of Grand Rapids in northwestern Ohio, in a landscape shaped by both the historic Miami and Erie Canal and the valley’s older natural history. Named for schoolteacher Mary Jane Thurston, who donated the first 14 acres in 1928, it grew through later additions and opened to the public in 1968. The surrounding Maumee Valley was once part of glacial Lake Maumee and later the Great Black Swamp, much of which was drained by 1875. Today the park preserves notable wooded land and supports year-round outdoor recreation and wildlife habitat.