Things To Do In Aniakchak National Monument and Preserve

The six-mile-wide caldera in the heart of Aniakchak National Monument and Preserve showcases what's left when a mountain literally blows its top.

But that's not all you'll find in this 600,000-acre park perched in Southwest Alaska near the start of the Aleutian Chain. The area is also well known for the wild Aniakchak River, which alternates peaceful stretches with challenging whitewater; and easy but trail-less walking across the caldera floor. But Aniakchak's greatest offering may be solitude, with only 150 visitors in a typical year.

Viewing the six-mile-wide, 2,500 ft (760 m) deep Aniakchak caldera, formed by repeated eruptions over millennia and complete with its very own, thermally warmed, lake--Surprise Lake.

Floating the wild Aniakchak River (a designated "national wild river"), which alternates between peaceful stretches and challenging, technical whitewater. It can take three or four days to float all the way from the river's headwaters at Surprise Lake to Aniakchak Bay.

There are no established trails in Aniakchak, but the caldera floor makes for easy walking. The only paths in dense vegetation are usually game trails, so be wary of surprise encounters and know how to react if they happen.

Fishing is allowed in accordance with Alaska Department of Fish and Game guidelines; sport hunting and trapping are allowed in the national preserve section of Aniakchak, but not in the national monument.

There are no roads or established services in Aniakchak Park and Preserve, which is located about 450 miles southwest of Anchorage. The weather is so unreliable that you should plan for delays to your pick-up and drop-off; take extra food and supplies to factor this in.

The visitor centre for Aniakchak is located in the nearby community of King Salmon. You can get from Anchorage to King Salmon aboard regular flights with Alaska Airlines and PenAir; the flight takes about an hour.

Summer is the easiest season for visiting Aniakchak, although "easy" might be a stretch. Summer weather tends to be cool, wet and stormy, with high temperatures ranging in the high 40s or low 50s (7 - 11 C). Fog, rain, overcast skies and stormy weather with violent winds capable of shredding tents and locking down air travel are all common. River conditions can change quickly and drastically.

Thanks to its explosive past, the local volcanic landscapes are unable to support much biodiversity but brown bears, occasional caribou and sockeye salmon spawning up Aniakchak River have all returned as the land slowly recovers.

• Aniakchak National Monument and Preserve measures slightly more than 600,000 acres; it was established as a national monument in 1978, and expanded to include the preserve in 1980.

• The impressive caldera was formed by a sequence of volcanic eruptions, the most recent of which was in 1931.

• Despite its great age, the caldera was only discovered by non-indigenous (European-descended) explorers in the early 20th century and is still only visited by just a handful of outsiders each year.