More Than 1,300 Golden Eagles in Three Weeks: Wrangell-St. Elias's Hidden Migration Flyways

For decades, the place to watch golden eagles migrate in Alaska was the Gunsight Mountain Hawk Watch. Earlier observers there suggested that more golden eagles pass Gunsight each spring than anywhere else in North America, apart from a few sites in the Rocky Mountains. What they could not know, and satellite tracking now shows, is that every golden eagle that passes Gunsight in spring has already flown through Wrangell-St. Elias National Park and Preserve.

A golden eagle over Wrangell-St. Elias. NPS / Jared Hughey.

Why here

Look at a map and it makes sense. The park lies at the northwestern curve of the continent, where several mountain systems bend together in a sweeping westward turn, and migration corridors follow those contours — sea ducks along the coast, blackpoll warblers inland. The people who drew the park's boundaries knew it mattered to nesting trumpeter swans and other waterfowl. Carol McIntyre, the NPS wildlife biologist who wrote this account, wonders whether they knew how much it mattered to other migrants.

Two corridors around the mountains

Tracking data from several projects mapped the spring routes. Breeding-age eagles fitted with transmitters by Alaska Department of Fish and Game biologists near Gunsight Mountain in 2014–2016 showed the birds avoiding the high Wrangell Mountains and using two corridors, one south of the high country and one north of it.

In many years, some eagles took the northern route before veering southwest past Gunsight.

Relocations of tracked golden eagles in spring migration, 1997–2024. The star marks the Mentasta Mountains study sites; the circle, Gunsight Mountain Hawk Watch. NPS.

Counting them

From mid-March to early April, 2020–2024, a team working on the southern flanks of the Mentasta Mountains — with Gunsight about 130 miles (210 km) to the southwest — to capture breeding eagles for tracking also counted the migrants, sometimes in passing and sometimes in dedicated searches. The counts did not cover the whole season, but in both 2022 and 2023 they recorded more than 1,300 golden eagles in the three-week study period.

Given what the tracking showed, it was no surprise that eagles per observation hour at the Mentasta sites were often higher than at Gunsight over the same weeks. Because the counts are a conservative minimum, far more eagles probably passed than were counted.

Golden eagles per observation hour, Mentasta Mountains and Gunsight Mountain, mid-March to early April 2021–2024. NPS.

What is still unknown

How many eagles use the southern corridor in spring, and how many more use either corridor after early April. But the tracking, the spring counts and earlier autumn observations together put parts of the park on Alaska's short list of places where raptors concentrate on migration.

A signature that protected a flyway

The park entered the National Park System when President Jimmy Carter signed the Alaska National Interest Lands Conservation Act, protecting, whether he knew it or not, some of Alaska's most important golden eagle corridors — places to rest and refuel on the way north. McIntyre finished her account in the week the nation was honoring Carter's legacy, and recalled his foreword to the 1982 book Alaska National Parklands, This Last Treasure, in which he wrote that these lands must go on being protected.

Sources

Based on "Using field observations and high-tech tracking technology to identify golden eagle migration flyways," by Carol McIntyre, wildlife biologist for Denali National Park and Preserve and the Central Alaska Inventory & Monitoring Network, National Park Service, Wrangell-St. Elias National Park and Preserve; drawing on Eisaguirre et al. (2018), McIntyre and Lewis (2016) and Fritz and Fritz (2011); a work of the United States government in the public domain.