By Tyler Allen Explore Big Sky Staff Writer

BOZEMAN – The Bridger Mountains every fall see one of the greatest Golden Eagle migrations in North America. In its 23rd season, the Bridger raptor count records the flight of these large birds of prey and 16 other raptor species on their way to southern wintering grounds.

Montana Audubon and HawkWatch International coordinate this effort with two observers perched on the helicopter pad at the top of Bridger Bowl ski area, armed with binoculars and sharp identification skills. The long-term data collected helps scientists learn more about raptor migration patterns as well as regional and continental population trends.

The Bridgers are located in a migration path called the Rocky mountain flyway and observers will count between 10 and 200 individual raptors – including Sharp-shinned Hawks, Cooper’s Hawks and Bald Eagles – each day, between Sept. 1 and Nov. 5. One of many observation sites scattered through the U.S., the Bridger site is unique because of the number of Golden Eagles spotted.

“The science is really important for measuring Golden Eagle populations,” said Steve Hoffman, Montana Audubon Executive Director and founder of HawkWatch International. “The Golden Eagles represent about half the total Bridger flight.” The Bridger data are especially important because declines in Golden Eagle populations across much of the West have been documented during the past decade.

The public is encouraged to hike to the top of the ridge and join the observers daily throughout the fall. They count from 10 a.m. to 6 p.m. and the best hours to see raptors are between 11 a.m. and 3 p.m. when there is stronger lift with higher temperatures, brighter sunshine and more afternoon wind. It’s a strenuous 2.5-mile, 2,000-vertical-foot hike so participants should be in relatively good shape.

Now through the first week of October is the ideal time to see many different species of raptors and anytime in October is great for observing eagles, Hoffman said.

The Bridger Raptor Festival from Oct. 4-6 is the highlight of the counting season, and includes a keynote address by Hoffman at the Museum of the Rockies Friday night. At Bridger Bowl on Saturday and Sunday the program continues with hikes, displays, lectures, kids’ activities and live bird presentations.

Find out more information at mtaudubon.org, hawkwatch.org and bridgerraptorfest.org. Hoffman visits the site about once a week and encourages the public to email him at shoffman@mtaudubon.org if they’d like a hiking companion.