Just southwest of Boise lies one of the last vast swaths of solitude in the United States.

The Owyhee Canyonlands, with stunning red gulches, winding rivers and a moon-like landscape where a volcano with a caldera once 600 times larger than Mount St. Helens erupted, stands as the largest unprotected wilderness area in the American West.

Locals might have once seen the Owyhees as the area’s best-kept secret: national park-quality wilderness without the tourists.

The Owyhee Canyonlands span Idaho, Oregon and Nevada. Conservations on the Oregon side want to see protections for the rugged desert area.