Koyukuk National Wildlife Refuge
Alaska Region   

Icon of Blue Goose Compass. Click on the compass to view a map of the refuge (pdf)




Meandering  Rivers.  USFWS.The Koyukuk National Wildlife Refuge has a high diversity of habitat types resulting from riverine erosion, deposition, flooding, the actions of wildfire, and topographical variation. River and larger creek corridors present a dynamic, shifting mosaic of habitats supporting many important species of wildlife on the refuge. As rivers and creeks meander through the flood plain, outside banks and vegetation are eroded into the river and inside banks are built up through the deposition of silt, sand, and gravel. New inside bank soil deposits are well drained and don’t freeze in the winter. Deeper bodies of water also don’t freeze solid in winter, and provide a form of insulation against permafrost. These factors create a steep habitat gradient away from river and creek channels represented by willow and alder thickets along gravel bars on the water edge, stands of cottonwood trees higher on the bank, giving way to bands of white spruce. White spruce forests typically grade into black spruce forest farther from the water. These are interspersed with bogs, tundra and grass lakes. Stands of broadleaf deciduous forest often mix with white spruce forest along river corridors and are also typically found on well drained slopes and on sandy deposits found throughout the northwestern portion of the refuge. A unique plant community occupies the shifting sands of the Nogahabara Sand Dunes in the Koyukuk Wilderness Area.

Find out more about the diverse habitats of the Koyukuk refuge:
Nogahabara Sand Dune

Last updated: April 4, 2010