Home to the third largest river in Alaska, this refuge provides year-round habitat for a variety of wildlife

The 3.5 million-acre Koyukuk Refuge is a classic river floodplain that is bisected by the Koyukuk River and surrounded by rolling, low mountains.


The Koyukuk River drains the southern side of the Brooks Range before merging into the Yukon River 500 miles later, making it the third largest river in Alaska. Within the refuge the river is surrounded by oxbow lakes, sloughs and shallow seasonally flooded basins called grass lakes. This tapestry of rich wetlands combines with lowland boreal forests to support a wide variety of birds.

Also located within the Koyukuk Refuge are the Nogabahara Sand Dunes. These dunes were formed thousands of years ago when sand exposed by receding glaciers was blown up against the Nulato Hills. Today the active dune area extends across 16,000 acres and contains individual dunes up to 200 feet in height and 300 feet or more in length. Nogabahara Sand Dunes are relatively inaccessible and are a designated wilderness area within the National Wilderness Preservation System.


Koyukuk National Wildlife Refuge is home to a wide variety of birds, mammals and fish of the boreal forest. Thousands of waterfowl, primarily wigeon, pintail, scaup, white-fronted geese and Canada geese are joined by both trumpeter and tundra swan on the Koyukuk's lush breeding grounds each spring. The refuge streams and lakes also sustain large fish populations including king, silver and chum salmon that migrate up the Yukon River. The Three Day Slough area supports about five moose per square mile while the Western Arctic Caribou Herd, numbering more than 425,000 animals, migrates through Koyukuk and the 300 strong Galena Mountain Caribou Herd lives within the refuge year round. More than 140 bird species, 30 mammal species and 14 fish species occur on refuge lands and waters.


Sport anglers are rewarded with some spectacular fishing at this refuge, with northern pike and sheefish found along virtually all of the refuges' rivers and tributaries, with Arctic grayling found in several of the clear, fast-flowing streams that feed into the Koyukuk River.

Subsistence and sport hunting are allowed on refuge lands in accordance with Alaska state and federal regulations. Moose and Caribou hunting are both popular on the Koyukuk Refuge.

Wildlife viewing is a year-round activity in the Koyukuk and Kaiyuh region. Visitors in the springtime will be treated to flocks of birds that use the refuge to nest. Bear viewing is prime in spring and early summer. Fall leaves provide a colorful backdrop for rutting bull moose and foraging bears and foxes. The winter is a time to learn about animal travel by tracks left imprinted in the snow. Caribou arrive in the lowlands, while wolves, lynx and smaller furbearers actively seek out prey.

Photography and rafting are also popular in the refuge. The scenic rivers and mountains, the wildlife and the magic hues of the long northern twilight add to the beauty of the scenery.

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