The Brooks Range is a 700-mile mountain wilderness hiding ancient secrets in northern Alaska.

Countries & Cities · Published 30 September 2026 Swipe more like this →

In short: Stretching across northern Alaska into Canada, the Brooks Range is a remote, 126-million-year-old mountain system. While mostly uninhabited, this rugged landscape serves as a critical migration corridor for hundreds of thousands of caribou and holds fossilized remnants of an ancient seabed, revealing a history far older than the peaks themselves.

Named in 1925 after USGS geologist Alfred Hulse Brooks, the range spans 700 miles from west to east. It acts as a primary drainage divide for North America, separating waters that flow toward the Arctic Ocean from those heading to the North Pacific. The mountains are geologically distinct, with rocks formed in an ancient seabed that still contain fossils of trilobites and brachiopods from the middle Cambrian period.

The region is a sanctuary for wildlife, including grizzly bears, Dall sheep, and massive caribou herds. The Porcupine Caribou herd, which migrates through the range, undertakes the longest migration of any terrestrial mammal on Earth. Despite its remoteness, the range is not entirely untouched; the Dalton Highway and the Trans-Alaska Pipeline System cut through Atigun Pass to reach oil fields at Prudhoe Bay. In the far west, the Red Dog mine operates as the world's largest zinc source.

Climate change is rapidly altering the Brooks Range. Between 1969 and 2018, the region experienced a warming rate twice that of southeastern Alaska, with average summer temperatures rising by 4.2 to 5.8 degrees Fahrenheit. This warming has caused a dramatic decline in perennial snowfields, which shrank from 34 square miles in 1985 to under four square miles by 2017. Additionally, the tree line is shifting northward, and shrub abundance is increasing in areas previously dominated by tundra, signaling a profound ecological transformation.

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