Mammoth Cave National Park Leads the Nation in Biodiesel Conversion

October 2003

Thanks in part to the assistance of the Kentucky Corn Growers Association and the Kentucky Clean Fuels Coalition, trucks, buses, heavy equipment, tractors-and even two ferryboats plying the Green River-are now using biodiesel fuel at Mammoth Cave National Park. The park's vehicles represent the first 100% alternative fuel fleet in Kentucky and the first national park in the country to install E85 fueling on site. This leadership in the alternative fuel arena contributed to the park's recognition as a "National Park of Environmental Excellence" by the U.S. Department of the Interior. It was one of 20 parks to receive this designation (of 385 parks in the system).

"There is a serious air pollution problem all over the southeastern United States," said Steve Kovar, facility manager of the park. "As a national park, we wanted to try something to correct it, or at least to do our part." So in 1998, the park began switching its fossil fuel vehicles to E85, a blend of 15% gasoline and 85% ethanol, created by fermenting the sugar found in corn. Last spring, the remaining fossil fuel light-duty vehicles switched to a 10% ethanol, 90% gasoline blend, which requires no vehicle modifications. The park installed an ethanol fueling station for these vehicles, thanks in part to the assistance of the Kentucky Corn Growers Association and the Kentucky Clean Fuels Coalition.

The park's heavy equipment switched from diesel to a biodiesel blend made from soybean oil or yellow grease, purchased from Valor Oil in nearby Bowling Green. Even the park's lawn tractors and its two ferryboats operating on the Green River are powered by biodiesel. Buses transport 400,000 visitors a year from a common parking area to the cave entrance; six of these were converted to propane.