Keeping it wild: how mules help preserve the last untamed places in the US

A mule at the historic Nine Mile ranger station, carrying the equipment to clear trails in the Bob Marshall Wilderness. Photograph: Jessica Reed/The Guardian

Here’s a partial list of things you cannot, under any circumstances, take into the Bob Marshall Wilderness, in Montana: chainsaws, mountain bikes, ATVs, tractors, wheelbarrows. If it has gears, it stays home. If it’s mechanical in any way, it’s a no-go.

Those are the rules deemed necessary to protect the United States’ 803 federally designated wilderness areas. The Bob Marshall Wilderness Complex, with its 1,849 miles of trails, happens to be one of the biggest.