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General:

• Located on the western edge of the Greater Yellowstone Ecosystem in Bonneville and Caribou Counties, Idaho.
• Includes one of the largest bulrush marshes in North America (13,000 ac)
• Significant breeding area for sandhill cranes, Canada geese, Franklin's gulls, and white-faced ibis.
• Marsh elevation 6386 ft.
• Caribou Mountain to east highest point within watershed (9803 ft).
• Ranching (cattle, sheep, hay production) predominant use of surrounding lands.

Climate:

• Average annual precipitation 17 inches.
• Average annual snowfall 115 inches; average accumulations of 40-50 inches.
• Daytime high temperatures average 68-75° in June and July.
• Hard frosts (<30°F) may occur in any month.
• Record high of 103°F recorded in 1919 and record low of –45°F in 1922.

Habitat and Plant Communities:

• Transitional zone between Great Basin vegetation (south) and Rocky Mountain vegetation (north).
• Within approved refuge boundary, 60% palustrine emergent wetland, 20% wetland semi-wet meadow, 12% brush, grasslands, and grainfields, 5% shallow open water with submergents, and 3% aspen forest and willow thicket.
• Over 170 species of grasses, sedges and forbs in wet meadows and marsh habitat, including 15 species of sedges.
• 3 species of exotic, invasive plants.
• 7 species of trees and 17 species of shrubs
• No known threatened or endangered plant species.

Wildlife:

• 128 recorded species of breeding birds present.
• Over 40 bird species nesting in the wet meadow and wetland habitats of the basin.
• 20 species of mammals.
• 4 species of amphibians.
• 6 species of reptiles.
• 2 species protected as "threatened or endangered" (peregrine falcon and trumpeter swan).
• Highest breeding density of sandhill cranes in North America - an important breeding area for Rocky Mountain Population of sandhill cranes.
• 700-800 cranes present in May; 1000 or more cranes stage in the basin in September.
• Nesting colonies of Franklin's gulls and white-faced ibis.
• Site of cross-fostering study of whooping cranes in 1970s-80s. Other methods were tested, but no further efforts are currently active and no whooping cranes or whooping-sandhill crane hybrids are present.

Water:

• Located within Willow Watershed, 651.45 mi² in size.
• Average water depth 3.5 m in spring; <0.5 ft in late July through September.
• Water sources from snowmelt and numerous springs; main inflow via Willow, Eagle, and Gravel Creeks on the east and south, and Crane Creek on the west.
• Original water outlet, Grays Lake Outlet, drains to the north into Snake River via Willow Creek.
• Clark's Cut, a man-made channel completed in 1924, drains into the Blackfoot Reservoir via Meadow creek.
• Water discharge controlled by the Bureau of Indian Affairs for use in Fort Hall Irrigation Project since the early 1920s.
• Drainage canals and drainage ditches were established during various periods (1920s, 1950s, 1960s).

Geology:

• Meade Thrust Fault principle structure underlying basin.
• Cretaceous rocks underlie Willow, Eagle, and Bridge Creeks, predominantly sandstones and shales.
• Paleozoic and Triassic rocks underlie Gravel Creek basin, predominantly carbonates with Quaternary alluvium covering lowlands.
• Tertiary volcanics (mainly olivine basalts) underlie most western drainage.
• Bear Island olivine basalt.

Access and wildlife viewing:

• Public road perimeter allows excellent bird viewing, particularly in May and early June when water levels are high.
• Viewing opportunities from Beavertail Point (south), refuge observation area (east), and north perimeter road.
• Access into marsh largely closed to the public to minimize disturbance of breeding sandhill cranes, trumpeter swans, and other waterbirds.
• Small Visitors Center at refuge headquarters; no other public facilities available.
• Access during fall waterfowl hunting on north half of basin.

Grays Lake National Wildlife Refuge

• Established 1965 for production of migratory waterfowl and other waterbirds
• Total area within proposed refuge boundary 32,825 ac.
• 18,330 ac within boundary controlled by refuge through fee-title, use agreements, other means.
• Active research program for adaptive management of habitat and wildlife populations.
• Management of grasslands and wet meadow using prescribed fire, grazing, idling, haying, and rotation systems.
• 3 year-round staff (manager, biologist, maintenance) and 2 seasonal maintenance staff.
• Research staff for projects 6-15 seasonally.
• Opportunities for interns and volunteers available for research and monitoring.

Mailing address:

     U.S. Fish and Wildlife Service
     Grays Lake National Wildlife Refuge
     74 Grays Lake Road
     Wayan, ID 83285
     Website: www.npwrc.usgs.gov/grayslk