Lone Elk Park is a county park in the U.S. state of Missouri consisting of 546 acres located in St. Louis County west of the town of Valley Park. The park is located adjacent to Interstate 44, the World Bird Sanctuary, Castlewood State Park, and Tyson Research Center. Lone Elk Park was originally part of the Tyson Valley Powder Plant during World War II. After the war the area became a county park and herds of elk and bison were established in 1948.