The third largest conservation area in the National Wildlife Refuge System, the 9 million acre Yukon Flats National Wildlife Refuge is located in eastern interior Alaska. It includes the Yukon Flats, a vast wetland basin bisected by the Yukon River. The basin is underlain by permafrost and includes a complex network of lakes, streams, and rivers. The area is characterized by mixed forests dominated by spruce, birch, and aspen. The Yukon Flats has a continental subarctic climate, with great seasonal extremes in temperature and daylight. Summer temperatures can reach 100 degrees F, warmer than any other comparable latitude in North America. Winter temperatures can drop to -70 degrees F.

The refuge supports the highest density of breeding ducks in Alaska, and includes one of the greatest waterfowl breeding areas in North America. In fact, most of Yukon Flats' birds are seasonal residents, fleeing south before the hard grip of winter closes over the land. Some 13 species, however (including boreal chickadees, great gray owls, spruce grouse, three-toed woodpeckers and ravens), remain on the refuge year around.

The same landscape that so favors waterfowl is also beneficial to furbearers, many of which, including beaver, lynx, marten, mink, muskrat and river otter, thrive on the water-laced flood plain. Moose benefit from the new growth encouraged by fire and flood, and can be found throughout the refuge. These large ungulates are the region's most important game animal; to the point that, for many subsistence hunters living on or around the refuge, "moose" is virtually synonymous with "meat."

Grizzly bears are found throughout the refuge in low concentrations, while the more common black bears tend to keep to the forested lowlands. Wolves can also be encountered anywhere on the refuge, but are rarely sighted. Dall sheep can be spotted on the alpine tundra of the White Mountains and Hodzana Highlands.

A rich ecosystem kept productive by fire and water.

On December 1, 1978, President Carter used his authority under the Antiquities Act of 1906 to create 17 national monuments in Alaska, including the "Yukon Flats National Wildlife Monument."