The Great Smoky Mountains National Park is going green with a fleet of propane-powered vehicles.

Park officials showed off six crew-cab trucks that have been converted to use propane fuel instead of gas Wednesday morning, along with two new propane fueling stations

The Smokies are among a growing number of National  Park Service units to begin using propane because it's better for the environment and saves the park money--- about 30 to 60 cents per gallon.

They also believe the change allows the park to do more without spending more.

"We increased our range, our driving range, by double, and decreased our down time substantially. So we have people in the field longer and it's less expensive," said Brian Bergsma, Deputy Chief of Facility Maintenance

The park has also converted a few grass mowers to use propane fuel.

This is the second round of funding that the park received to help advance their cleaner fuel and energy initiatives.