This 2.7-million-acre reserve on western Alaska’s Seward Peninsula is sprinkled white with cotton grass during its brief summer, when high temperatures barely reach into the 50s. It ranks as one of the most adventure-worthy and least-visited units of the National Park Service. You can only access the preserve by plane, boat, snowmobile, or dog sled. But the rewards of hiking this trailless backcountry tundra more than make up for the tricky logistics.
Plan for a week to tour Devil Mountain Lakes, Killiak Lakes, and White Fish Lake, some of the largest geothermal lakes in the world (called maars); dip into Serpentine Hot Springs; watch herds of muskox; and view the wrinkled, 88-square-mile Lost Jim Lava Flow. Dispersed camping is permitted anywhere, but be mindful of bears—grizzly and polar.