Tourists who come to see Yellowstone's Old Faithful probably won't notice what's right under their feet.
A new, spongy footpath made in part from 900 used tires leads visitors to the West's most famous geyser. And it does something else too: The material protects the gusher that sends off steam and water about 130 feet into the air every hour or two.
Over the years, the challenge for park officials was to figure out how to accommodate the majority of the 3.5 million annual park visitors who come to see Old Faithful while making sure the sensitive ecosystem around the geyser isn't harmed.
The old asphalt route used by visitors was breaking up and forcing park officials to close parts of the walkway at times.
The new material, called Flexi-Pave by a company called KBI, combines recycled tires with other materials to create a porous path that helps retain the groundwater the geyser needs and helps control erosion too.
And it didn't cost the park a dime.
Michelin donates tires for the parks tractor trailers, patrol cars, garbage trucks, etc., each year. The park used donated tires -- which had come to the end of their lifespan -- in making the footpath material, and Michelin ponied up volunteers to complete the 6,400-square-foot upgrade.
So the next time you're waiting for Old Faithful to spew, take a minute to look down at the path that keeps it healthy.