Bridger Mountain Birds of Prey
Each autumn, birds of prey concentrate along the Bridgers in their migration south. 17 species
can be seen here between late August and early November. Most notable is the Golden Eagle.
Raptors are inspirational creatures for our spirits and important species by which to measure
the quality of the natural environment. In addition to the diversity of hawks, falcons, and
eagles visible, this site hosts the largest concentration of migrating Golden Eagles in the lower 48 states.
Public Welcome!
The public is encouraged to visit the Bridger Mountains and view these magnificent birds of prey
during the fall migration season. Although the migration lasts several months, the best raptor watching
typically occurs during the first two weeks of October with the greatest variety in species occurring
between 10 a.m. and 2 p.m. Up to 280 migrants have been seen in one day.
Where to Go
There are two good viewing sites. Both sites are in the Gallatin National Forest on top of
the Bridger Range. They include spectacular views of the Gallatin and Shields Valleys and eight surrounding
mountain ranges. Strong ridgetop winds are typical; visitors are encouraged to take along warm clothing and wind
protection. There are no facilities on the ridge--be sure to bring up whatever food and water you need.
1. Bridger Bowl - this site is located at the top of Bridger Bowl Ski Area above the
Bridger Lift. This is also where HawkWatch International and the Forest Service maintain a raptor monitoring
station during September and October. The observers will gladly answer questions and will help
visitors identify birds.
To get there from Bozeman, take Highway 86 north and follow the Bridger Bowl Ski Area signs (see
map). At the ski area, follow the main gravel road staying right of the lodge and ski parking area. Follow the road to a Forest Service gate.
Follow the main road past the ski lift and side trail and walk up the ski run to the right until you cross a dirt maintenance road; follow the switchback road
to the head of the ski lift. A footpath near the lift operator's building will lead you to the viewing platform. The
climb from the gate is 2100' in elevation and will take 1 1/2 to 2 hours.
2. Sacajawea Peak - this viewing site is the highest point in the Bridgers (9600') and is a
popular hiking destination because of the magnificent views and alpine terrain. Follow the Sacajawea
Trail that starts at the Fairy Lake Campground; it is a 2 mile hike, climbing 1900', and will
take over 1 hour. There are no personnel at this site to aid in raptor identification.
To get there go 22 miles north of Bozeman on Highway 86. Turn left onto the Fairy Lake
Road (signed FDR #74); follow the gravel/dirt road to the Fairy Lake Campground and
Trailhead.
Open House
Each fall HawkWatch International, the Forest Service, and volunteers host an open
house - Eagle Day! This occurs during the peak of migration in early October. There are
interpretive talks and skilled raptor watchers to assist you with identification and spotting. Eagle
Day is held atop Bridger Bowl Ski Area. Contact the Bozeman Ranger Distriact of the Gallatin National Forest for
information.
What to Look For
Most raptors are identified at a far distance. In addition to a good pair of binoculars, knowing the silhouettes of the
different hawk species is very useful in identification.
Accipiters
- Sharp-shinned Hawk - small head, butterfly like flight.
- Cooper's Hawk - larger head, steadier flight, long scoop shaped tail.
- Northern Goshawk - heavier, tube shaped body, almost buteo-like.
Harriers
- Northern Harrier - long tail, somewhat pointed wings, white rump patch.
Falcons
- American Kestrel - small, reddish brown, long tail, flappy flight.
- Merlin - small, dark streaked falcon, very fast.
- Prairie Falcon - larger, dark wing-pits, sandy brown.
- Peregrine Falcon - same size and shape as Prairie Falcon but darker.
Buteos
- Red-tailed Hawk - dark mark on leading edge of wing, adults have red tail.
- Rough-legged Hawk - similar to Red-tailed but with single banded tail, lanky.
- Broad-winged Hawk - smaller, chunky buteo. Adults have banded tails.
Eagles
- Golden Eagle - large, almost flat wing profile, mostly dark with juveniles having white patches
under wing or under tail.
- Bald Eagle - large with perfectly flat wing profile. Adults have white head and tail. Juveniles are mottled black and white.
Raptors Galore!
At least 17 species of raptors have been seen atop the Bridger Mountains. The most common are
Golden Eagles, Bald Eagles, Northern Harriers, Sharp-shinned Hawks, Cooper Hawks, Red-tailed Hawks, and
American Kestrels. One of the largest raptors with a wingspan of 7 feet, the Golden Eagle is a masterful hunter and powerful flyer.
Daily counts of over 200 Golden Eagles are possible during early October. The season starts with a trickle
of Ospreys and falcons, climaxes with hundreds of GOlden Eagles and Sharp-shinned Hawks, and trails off with Bald Eagles
and Rough-legged Hawks. Each autumn, an observation team atop the Bridgers counts raptors
as part of an international effort to study these magnificent birds.
Heading South
The concentration of raptors (birds of prey) is associated with the fall migration.
Hawks, eagles, and falcons, sensing the shortening day, cooler weather, and less abundant prey migrate south. The Goshawk, Bald Eagle, and Golden
Eagle may only be migrating a few hundred miles south. Long distance migrants such as the Osprey, Peregrine Falcon, or
Swainson's Hawk may fly to Mexico or beyond. Many of the raptors seen have spent their
summers in the eastern Rockies or Great Plains. Most birds are juventiles, born just months ago. The high mountains act as a funnel
for raptors. Westerly winds produce updrafts along north-south ridges such as the Bridgers. By
utilizing such terrain, a bird of prey can conserve energy for the long flight ahead.
Counting Raptors
Every Spetember and October, HawkWatch International coordinates a team (supported by
the US Forest Service and Bridger Bowl Ski Area) to monitor the autumn migration, counting and identifying.
The Bridger site is but one site in a network of 10 sites in the west managed by HawkWatch
International. Nationally, there are another two dozen sites devoted to counting these
hunters of the sky.
Why Count Raptors?
Raptors help us by acting as ecological barometers. They feed at the top of the biological food chain, occupying grasslands,
forests, deserts, arctic tundra, and wetlands all over our planet. They are sensitive indicators
of changes in the ecosystems, not only within our country but across political borders. As do many predators,
raptors play a critical role in maintaining ecosystem health.
Larger birds such as the Golden Eagle prey on rabbits and small mammals. Red-tailed Hawks and other
buteos feed mostly on gophers, ground squirrels, and mice; while smaller falcons and accipiters
prey upon small birds and mice.
The yearly trends in data from the Bridgers and other hawk watch sites point out rises or
declines in species numbers. This information is useful to biologists and conservationists.
The Bridger hawk watch site is sponsored by:
US Forest Service
Bridger Bowl Ski Area
HawkWatch International
If you are interested in learning more about raptor monitoring, contact:
HawkWatch International
PO Boz 660
Salt Lake City, UT
84110-0660
Phone (801) 524-8511
This Web presentation is based upon a brochure produced in partnership between
Gallatin National Forest, HawkWatch International and Chad Moore.