Most hikers use the Appalachian Mountain Club’s “White Mountain Guide” to pick and choose specific hikes they want to tackle.

But some hikers decide to hike every single trail in the book – all 1,420 miles of trail in the White Mountains.

Doing so is called “redlining” — the idea being that you draw a red line over every completed trail — and it has become increasingly popular.

The Boston Globe recently did an article on redliners. Much of the hiking when redlining takes place outside of the popular trail networks that support the highest peaks, leading redliners to obscure, seldom-used trails all over New Hampshire and western Maine. Redliners say that to complete every trail, they have to cover some sections more than once. Altogether, they might easily cover between 3,000 to 4,000 miles by the time they’re done.

Redliner Beth Zimmer says its a novel way to experience hiking in the Whites. “It’s forced me to hike trails that are very difficult, very remote, but at the core you’re really in the moment,” says Zimmer.

Read about hikers “redlining” the White Mountains.