Nine of the 13 National Parks will begin using alternative-fuel vehicles this summer under the U.S. Department of Energy's Clean Cities program to improve fuel efficiency and reduce vehicle idling.

The projects were announced by the DOE in late March and are expected to reduce petroleum use by more than 16,000 gasoline gallon equivalents and cut tailpipe emissions by 109 metric tons of greenhouse gas emissions.

The programs will add 24 alternative-fuel vehicles, nine propane mowers, and 18 electric vehicle charging stations. The vehicles include 10 electric and plug-in electric vehicles, seven low-speed electric vehicles, four propane autogas vehicles, and three hybrids.

The projects will roll out at Acadia National Park in Maine; Catoctin Mountain Park in Md.; Florissant Fossil Beds National Monument in Colo.; Great Smoky Mountains National Park in Tenn.; Nicodemus National Historic Site in Kan.; Petroglyph National Monument in N.M.; Pea Ridge National Military Park in Ark.; Scotts Bluff National Monument in Neb.; and Zion National Park in Utah.

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