Caribou Tracks, Gates of the Arctic National Park, Alaska

Hiker: Terry Tempest Williams, author and environmental activist

Hike-ware equipment used: G-Receiver III and Hiker 1.0

In Her Words

The trail I dream of walking? Any caribou trail in Gates of the Arctic National Park or Arctic National Wildlife Refuge. Sometimes when I close my eyes, I can hear their clicking ankles on the tundra, and I imagine walking behind them in silence in that vast expanse of wilderness. —Terry Tempest Williams

Length: The caribou migrate 120 to 400 miles

The Details: The northernmost park in the U.S., Gates of the Arctic National Park and Preserve covers 8.4 million acres in the Brooks Range just above the Arctic Circle. It has no trails and protects the habitat and migration routes essential to the Western Arctic Caribou Herd, which has been declining but still numbers approximately 325,000 animals, making it the largest in Alaska. The 19.3-million-acre Arctic National Wildlife Refuge and Preserve (ANWR) is probably the most well known and hotly debated wilderness in the United States due to two natural resources it has in abundance—caribou and oil. ANWR is a massive place consisting of mountains, tundra, and coastline with few visitors, no trails, and a menagerie of Arctic wildlife.

The best known of those species is the caribou. Two herds live here and over the border in Canada: the Porcupine Herd (about 169,000 animals) and the smaller Central Arctic Herd (42,000). In spring, the Porcupine caribou come together to make their great migration to calving grounds hundreds of miles away on the coastal plain. The Porcupine herd leaves the coastal plain by mid-July, mostly to avoid hatching mosquitos, and begins to head into the foothills. In fall, they move en masse again, heading south into the Brooks Range and Yukon Territory. The Central Arctic Herd follows a slightly different route.

The conflict in ANWR is over 1.5 million acres of coastal plain, known also as 1002 Area. Not only is it the calving ground for the caribou, it’s also the site of one of what could be the largest known onshore oil and gas reserves in the United States. For now, the only activity here is from the thousands of caribou. It's possible to sign on with outfitters who will take you out to hike along with them as they make their migrations in Gates of the Arctic—which has no drilling conflict—or ANWR. It is one of the few great wildlife wonders left on the planet.

When to Go: Spring and fall, when the caribou undertake their great migrations