The Upper Henry?s Fork, of which Henry's Lake is part, is widely recognized as a keystone landscape in the Greater Yellowstone Ecosystem and the northern Rockies. The Bureau of Land Management (BLM) has designated the public land surrounding Henry?s Lake as an Area of Critical Environmental Concern. Idaho Fish and Game has also documented the region as one of the most valuable wetland complexes in the state. In a recent study of the regions surrounding Yellowstone National Park, the Upper Henry?s Fork and in particular the area surrounding Henry?s Lake, was singled out as the single most important landscape in the Greater Yellowstone Ecosystem in terms of its value to wildlife. The region was also recognized as the second most ?threatened? by development and shifting land use. The Nature Conservancy (TNC) sees the Henry?s Lake area as one of the most exceptional natural landscapes in Idaho and recognizes the important role private ranchlands play in maintaining the unique balance of aesthetic, cultural, economic, and ecological values that define the area.

From bird conservation perspective the region is breeding habitat for sandhill cranes, long billed curlews, trumpeter swans, peregrine falcons and bald eagles, to name a few. It also represents stopover habitat for thousands of ducks and geese, as well as shorebirds, including hundreds of American Avocets. The interface of montane and aquatic resources, as well as intact and healthy riparian and lacustrine wetlands, provide excellent habitat for a large suite of avian species.

Ornithological Summary

Henry?s Lake is incredible habitat for waterfowl, shorebirds and other waterbirds. In May 2007, migration surveys estimated 4000 waterbirds using the general area, including over 1600 Franklins Gulls.

The lake provides habitat to trumpeter swans, grebes, coots, gulls, terns, pelicans, avocets, stilts, cormorants, loons, eagles, osprey and dozens of species of ducks.

Henry?s Lake Flat and the rangelands and wetlands around Henry?s Lake support additional populations of waterfowl and shore birds but provided critical habitat for Sandhill Cranes, Long-billed Curlews, great blue Herons, Black-crowned Night-herons, bitterns, soras, killdeer, greater sage grouse, and many species of upland raptors including Swainson?s hawks. Red Tailed Hawks, Peregrine Falcons, and Northern Harriers. During migration, between 70 and 250 buteos have been regularly observed on the flats since the 1970s.

Conservation Issues

Rural residential development is the number one threat to this area. Habitat conversion threatens water quality, wetlands, open space, and forested nesting areas. Other threats include invasive species, loss of riparian habitat due to poor water management, and loss of habitat to overgrazing. To help combat these issues, TNC launched the Henry?s Lake Ranchland Protection Program in 2002. This public/private easement acquisition program has been a focused effort to develop landowner, local community, foundation, and political support to protect the approximately 17,000 acres of undeveloped ranchlands in the region over a 10-year period. Though TNC plays a leading role in the acquisition program, they work closely with an extensive partnership including the BLM, the Teton Regional Land Trust, The Conservation Fund and the Natural Resources Conservation Service. This program is projected to cost $30 million. To date the program has protected around 4,500 acres. The total value of the land TNC has worked to protect is just under $3.5 Million.


Idaho Department of Lands, BLM, and USFS are the largest land owners in the region. The private landscape is a smaller but more important portion in light of bird conservation. TNC works with these private land owners and will act as liaison.


Henry?s Lake is best characterized by the open grasslands which surround the lake and the historic lakebed of the Henry?s Lake Flats. The grasslands are primarily hay grasses and are predominately introduced bromes and timothys. There is limited intact sage-brush on the south east and west sides of the lake. The mountains surrounding the region are almost entirely lodgepole pine and Douglas fir with fringes of aspen. The region gets approximately 19? of precipitation per year most in the form of snow. There are approximately 45 frost free days in the summer limiting the agricultural influence. Soils are excellent in places with deep mollisols, while other places are very coarse loams and glacial cobbles.

Land Use

Generations of people have visited and enjoyed Henry?s Lake. It is a stop for many on their way to Yellowstone National Park. The historic ranchlands and open space that characterize the landscape are valued by many but are under threat from development. Fremont County makes a good portion of its tax revenues through fisherman and hunters who value the open space and wildlife of the region. Fishing and boating are popular around the lake, with two public boat ramps available. One ramp is located within Henrys Lake State Park at the southern end of the lake. At the northern end of the lake there is a state fish hatchery.

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