Great Rivers Greenway is the public organization leading development of the River Ring, a region-wide system of interconnected greenways, parks, and trails that will join two states and cover an area of 1,216 square miles. Formerly known as the Metropolitan Parks and Recreation District, Great Rivers Greenway was established in November 2000 through the successful passage of the Clean Water, Safe Parks and Community Trails Initiative (Proposition C) in St. Louis City, St. Louis County, and St. Charles County, Missouri.