[5] A portion of the vast Western Arctic caribou herd utilize the Kobuk River valley as winter range.

Lt. J. C. Cantwell, USRCS, also explored the river in 1884 and 1885 and spelled the name "Koowak" on his map and "Kowak" in his text.

Lt. H. T. Allen, US Army, transcribed the Koyukon Indian name for the river in 1885, which he spelled "Holooatna" and "Holoatna.

However, actual precipitation can range from 15 to 40 inches (40–100 cm), with greater amounts falling in the upper reaches of the river basin.

[9] Records of air temperature from 1961 to 1990 logged at the latitudes of the Kobuk River show a warming trend of about 1.4 °F (0.78 °C) per decade.

[9] Climate change is presently considered the most severe environmental stress in the Kobuk River Basin and throughout Alaska.

The Kobuk's current form and structure is a direct result of several stages of erosion and channel formation following the last glacial retreat.

The river picked up glacial till from its upper reaches and transported it downstream until the gradient diminished.

When the river encountered flatter ground, it deposited its sediment load resulting in the creation of broad, flat floodplains, alluvial fans, and meander bends through aggradation.

[12] After the first stage of aggradation and sediment transport, the Kobuk began a new phase of erosion and landform development.

[citation needed] These large sand dunes are the modern ancestor of alluvial deposits that became shaped and dominated by an exchange of aeolian and fluvial processes.

In times of drier climate, wind dominates and blows a lot of sediment into a weaker fluvial system, leading to aggradation and floodplain re-distribution.

Currently, the Kobuk River in its middle and lower reaches is an anastomosing stream, with several braided channels in places, wide migrating meander bends, and oxbow lakes.

Lastly, since the river is surrounded mostly by permafrost and because during the spring break-up event there are still large parts of frozen ground close to its banks, floods often transport large amounts of fine sediment across broad expanses of floodplain in thin sheets of water that slide easily across the frozen ground.

Farthest west, the Kobuk empties into Hotham Inlet, the easterly arm of Kotzebue Sound.

During recent geologic times, however, when sea level was lower, the Noatak, Kobuk, and Selawik Rivers were joined.

[13] As the snowpack begins to melt toward the end of May, flow in the Kobuk River increases with most of the runoff occurring during June.

[3] Most of the major tributaries of the Kobuk River flow from the north, draining the mountains in the southern Brooks Range.