Natural World

"Do you have tigers in your park?" asks one student doing a report on Kobuk Valley National Park. Sadly no, but they do have grizzlies, mink, loons and wood frogs. People catch many salmon in the Kobuk River. We also know that this is the only place in the world where you can find the Kobuk Locoweed. The largest caribou herd in Alaska - about 490,000 animals - travels through this area during its migration. Inventory and monitoring efforts combined with traditional ecological knowledge provide information about the park's natural resources. Currently, we estimate that there are 400 plants, 119 birds, 32 mammals, 23 fish, and 1 amphibian.

The park encompasses the Baird Mountains in the north, the Kobuk Sand Dunes in the south and the broad Kobuk River Valley in between. All together, this equals 1.7 million acres. The southern boundary of the park is 35 miles above the Arctic Circle. The boreal forest reaches its northern limit here, resulting in an open woodland of small trees in a mat of thick tundra. The Kobuk River winds its way slowly through the park for 61 miles.

The park was established to maintain the environmental integrity of the valley's natural features in an undeveloped state and, in cooperation with local Natives, to protect and interpret archeological sites associated with Native cultures. As such, natural and archeological objects are protected. Leaving them where you find them preserves these special resources for the good of residents and visitors alike.

Sand, Rivers and Caribou

Kobuk Valley National Park is encircled by the Baird and Waring mountain ranges. The park povides protection for several important geographic features, including the central portion of the Kobuk River, the 25-sqaure-mile Great Kobuk Sand Dunes, and the Little Kobuk and Hunt River dunes.

Sand created by the grinding action of ancient glaciers has been carried to the Kobuk Valley by both wind and water. Dunes now cover much of the southern portion of the Kobuk Valley, where they are naturally stabilized by vegetation. River bluffs, composed of sand and standing as high as 150 feet, hold permafrost ice wedges and the fossils of Ice Age mammals.

Nearly half a million caribou migrate through the Park twice a year – north in the spring, south in the fall. Their tracks crisscross the 25 square miles of the Great Kobuk Sand Dunes. The lofty dunes are a sculpted desert in the middle of a wilderness of wetlands. The Kobuk River on the north side of the dunes winds roughly 61 miles through the park, providing a travel path for people and wildlife.

Onion Portage is a National Historic Landmark on the Kobuk River where people gathered for 9000 years to harvest caribou as they forded the stream. Today, local Alaskan residents still feed their families with caribou from the river crossing in the fall.

Sand and Glaciers

While no glaciers currently exist within the park, at least five major Pleistocene glaciations have been identified in Northwest Alaska. The greatest of these glacial events occurred during Illinoisian time when glaciers extended west to the Baldwin Peninsula. The two earlier glaciations, the Kobuk and Ambler glaciations, covered large areas of the Kobuk and Selawik valleys, as well as the drainages of the Baird Mountains. The three later glaciations were restricted to portions of the Schwatka Mountains, east of the park.

During the interglacial period between the Kobuk and Ambler glaciations, glacio-fluvial deposits on river bars and outwash plains were worked by strong easterly winds. The down-valley movement of large volumes of silt and sand created dune fields (eolian deposits) which cover an area of approximately 200,000 acres. Most of this dune area is currently vegetated by tundra and forest, except for the three active dunes - the Great Kobuk Sand Dunes, the Little Kobuk Sand Dunes and the Hunt River Dunes. These active dunes cover approximately 20,500 acres. The Great Kobuk Sand Dunes lie less than two miles south of the Kobuk River, immediately east of Kavet Creek, and the Little Kobuk Sand Dunes lie about five miles south of the Kobuk River, in the southeastern portion of the park. The hunt River Dunes are located on the south bank of the Kobuk River at the mouth of the Hunt River.

The Great Kobuk Sand Dunes display a complete and readily observable sequence of dune development, from the U-shaped, concave dunes with vegetative cover in the eastern portion of the field, to the crescent-shaped, unvegetated barchan  dunes, which stand over 100 feet in height, in the western portion. It is the largest active dune field in arctic North America.