Koyukuk National Wildlife Refuge

Homeland of Koyukon Athabascans, the 3.5 million acre Koyukuk National Wildlife Refuge lies within the extensive floodplain of the Koyukuk River of interior Alaska, about 270 miles west of Fairbanks. The refuge's rich wetlands combine with lowland boreal forests of spruce, birch and aspen to support a diversity of wildlife, from healthy numbers of moose populations to large waterfowl populations from four continental flyways. 

Within the boreal forest of the refuge, a unique geological feature is found: the Nogahabara Sand Dunes. The roughly circular active dune field spans about six miles in diameter, and was formed thousands of years ago when wind-blown glacial sand was deposited at the base of the Nulato Hills. One needs only to step to the top of a 50-foot high dune to recognize its uniqueness. This active dune area contains about 16,000 acres and is only a small part of a Pleistocene dune field that is now mostly inactive. Four-hundred thousand acres of the refuge, including the dunes, are designated as Wilderness.