For more than 20 years, hikers have struck out on June’s first Saturday to confirm what America’s most famous naturalist, John Muir, noted more than a century ago: “Wildness is a necessity.”

The occasion, National Trails Day, celebrates the nation’s more than 230,000 miles of trails. It’s a network that continues to expand, thanks to a decades-long effort to convert abandoned rail tracks into walkable green spaces.

New York City’s High Line – a roughly 1.5-mile elevated trail cutting across a western portion of Manhattan – might be the highest-profile example of a rails-to-trails project. But no state has done more to put old track to good use than Pennsylvania.

Source: Best state in America: Pennsylvania, for turning old rails into trails – The Washington Post