John Martin
History
Regulations
The Bald Eagle is truly an all-American bird
– it is the only eagle unique to North America.
It ranges over most of the continent, from the
northern reaches of Alaska and Canada south to
northern Mexico.
• The State Park is open from 5 am to 10
pm daily. A Colorado State Parks Pass is
required on all vehicles.
• The State Park closes campsites 39 through
109 in the treed area of the Lake Hasty
Campground from November 1 to March
31 of each year to provide an undisturbed
and protected area for Bald Eagles to roost,
loaf, hunt, and/or rest. The large trees in
this area also help protect the eagles from
the wind and weather. Visitors to the Park
during this time should be particularly
careful in controlling their pets and noise
levels if Bald Eagles are roosting in the area.
• Both the north and south shore areas of John
Martin and the reservoir are closed to all
public access from the waterfowl closure
line east to the dam from November 1 to the
end of waterfowl season or as posted.
• Bald Eagles are protected by the
Endangered Species Act, the Migratory
Bird Treaty Act, and the Bald and Golden
Eagle Protection Act. Anyone who harasses
or harms a Bald Eagle may be assessed a
maximum penalty of $100,000, up to
three years in jail, suspension of hunting
and fishing privileges, and/or forfeiture
of any vehicles/vessels used in
the disturbance.
When America adopted the Bald Eagle as
its national symbol in 1782, as many as 100,000
nesting Bald Eagles lived in the continental
United States, excluding Alaska. However, due
to years of human persecution, habitat loss, food
source reduction, and impaired reproduction
caused by environmental contaminants,
especially DDT, only 417 nesting pairs were
found in the lower 48 states by 1963. The Bald
Eagle was listed as endangered throughout
most of its range (including Colorado) under the
Endangered Species Preservation Act of 1966 and
the Endangered Species Act of 1973.
Today the American Bald Eagle has made
a tremendous comeback. Since the banning of
DDT in 1972 and with intensive protection efforts
through partnerships between federal, state, and
local governments, conservation organizations,
universities, corporations and thousands of
individual Americans, Bald Eagle populations
have increased throughout much of the United
States over the past three decades. As a result
it is estimated today that there are over 5000
nesting pairs of Bald Eagles. The Bald Eagle
was reclassified from endangered to threatened
throughout its range in the lower 48 states in 1995
and the U.S. Fish & Wildlife Service proposed
de-listing the Bald Eagle in 1999. To date no
final determination has been made on this
de-listing proposal.
For Further
Information
Colorado State Parks
John Martin Reservoir State Park
30703 Rd. 24
Hasty, CO 81044
719-829-1801
john.martin.park@state.co.us
www.parks.state.co.us
Colorado Division of Wildlife
Lamar Area Office
1204 East Olive
Lamar, CO 81052
719-336-6600
Department of Natural Resources
1313 Sherman Street, #718
Denver, CO 80203
303-866-3311
U.S. Army Corps of Engineers
John Martin Reservoir
29955 Rd. 25.75
Hasty, CO 81044
719-336-3476
U.S. Fish and Wildlife Service
755 Parfet Street, Suite 361
Lakewood, CO 80215
303-275-2370
www.fws.gov
at
John Martin Reservoir
State Park
Physical Characteristics
The Bald Eagle is the most recognized raptor
(bird of prey) in North America. The Bald Eagle is
a large brownish-black bird with distinctive white
head and tail feathers, which appear only after
the bird, is 4 to 5 years old. Young Bald Eagles
are mostly dark brown until they reach four to
six years of age and may be confused with the
golden eagle. This striking raptor has large, pale
eyes; a powerful yellow beak; and great black
talons. Females can weigh up to 14 pounds and
have a wingspan up to 8 feet. Males are smaller,
weighing 7 to 10 pounds with a wingspan of
6 feet. The bird’s life span in the wild can reach
30 years.
Eagles at
John Martin
Habitat & Diet
Bald Eagles are found in association
with estuaries, large lakes, reservoirs,
major rivers, and some seacoast areas.
In winter, Bald Eagles congregate at
specific wintering sites that are generally
close to open water and offer good
perch trees and roost sites. Roost sites
are usually in tall trees in areas that are
protected from the wind, weather, and
human disturbance.
Their diet consists largely of fish and
waterfowl, but also includes upland
birds, small mammals (prairie dogs,
rabbits, etc.), and carrion. Bald Eagles
are skilled hunters, but are opportunistic
predators and will steal prey captured by
other raptors.
During the winter months, Bald
Eagles can be seen throughout the area
flying, standing on the ice, and perched
or roosting in tall trees. John Martin
Reservoir and the surrounding area are
considered essential winter habitat based
on the number of eagles using the area
and duration of use. In January of 2001
an aerial census documented 58 eagles
using the area. That number increased
to at least 126 eagles during the winter of
2001-2002. Bald Eagles begin to arrive in
November and stay until mid-March and
use the area for hunting, feeding, loafing,
and roosting. To date no breeding
activities have been observed.
Bald Eagle numbers vary from year
to year. Not all factors influencing this
variation are known although winter
weather conditions appear to have an
effect. During severe winters, northern
lakes and reservoirs freeze prompting
Bald Eagles to migrate south in search
of preferred habitat (large open water
areas with an adequate food base, good
perch trees, and protected roost sites).
Conversely, during mild winters, Bald
Eagles do not have to migrate this far
south to find preferred habitat. In
addition to weather conditions, water
levels also appear to affect Bald Eagle
numbers. During high water years,
waterfowl populations (food source) increase
and there are larger areas of open water for Bald
Eagles to hunt. During low water years, the
opposite is true.
Viewing Ethics/Hints
• Dawn and dusk are the best times
to view.
• Use binoculars or a spotting scope
so that you can view eagles from
further distances.
• View eagles without changing
their behavior. Give them plenty
of space. Eagles are sensitive to
human disturbance.
• Be respectful of perching and roost sites.
Well-meaning but intrusive visitors can
cause an eagle to flee its roost. This leaves
an eagle susceptible to the elements during
inclement weather and causes undue
stress, which reduces its fitness going in to
breeding season. Visitors who get too close
may also scare an eagle from its hunting
perch, preventing it from
capturing prey.
• Keep pets on a leash or
leave them at home. Pets
may startle, chase, or
even kill wildlife.
• Let animals eat their
natural foods. Pick up
all trash and food scraps.