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©2002 Cascadia Times

Top 10 western rivers trampled by the livestock industry

6 Sweetwater River - Wyoming

When the wetlands are lost

Cattle grazing is making the effects of drought more severe along the Sweetwater River as it flows down the eastern flank of the Wind River Mountains, near the Oregon, California, Mormon and Pony Express trails, and past Independence Rock and Devil's Gate.

Cows run over 1 million acres public lands north and south of the river, trampling and overgrazing its ancient riparian wetlands.

"These riparian wetlands may have formed as early as 2,000 years ago," says Ray Corning, a retired fishery biologist who lives in Lander, Wyo. "Sheep were grazed for many years in much of this area with little lasting damage to riparian wetland areas. All this changed when sheep were replaced with cattle in the 60s and early 70s. Cattle grazing has nearly eliminated the water retaining capabilities of the various riparian wetlands in less than 50 years."

Overgrazing prevents the replenishment of dead organic matter formerly supplied by sedges, grasses, and other vegetation, says Corning, who at one time was principal fisheries biologist for the Bureau of Land Management. Most riparian wetlands of the Sweetwater Drainage are in a perilous condition because of the rapid rate at which this dead matter - known as humus - is being eroded. "Conditions are further exacerbated by overgrazed wetlands and surrounding uplands, as former snow trapping abilities may have been lessened by as much as 70 fold through decreased vegetative height," Corning says.

The consequences would be dire in normal years, but severe drought has reduced flows in the Sweetwater. By losing its wetlands, the river basin can store much less water to cushion the drought's effects.

"The local drought that may be entering the third year has only emphasized the importance of good functioning wetlands," Corning says. "Well functioning riparian wetlands could have made a significant difference during this period of drought, both locally and within Wyoming.

The Sweetwater basin is habitat for sage grouse, an imperiled species, and for antelope, elk and moose. The lower valley is used by bald eagles in winter. Peregrine falcons migrate and nest in the area. White-tailed prairie dog towns provide potential food for the nearly extinct black-footed ferret. The Sweetwater River has high value habitat for nesting and migrating mallards, sand hill cranes and Canada geese.

Cattle, unlike sheep, congregate on riparian wetland habitats during hot weather for much of each 24-hour period. Riparian and riparian wetland habitats are the coolest areas during hot weather, and they provide the most succulent forage for cattle.

In 2000, the first year of drought, the Bureau of Land Management allowed cows to overgraze the valley. In 2001, with conditions even more severe, the BLM ordered cattle off a portion of the range by August 22. Ranchers accused the BLM of having a policy of "save everything but the rancher."

The BLM is now conducting an environmental rangeland health assessment of grazing covering the entire Sweetwater drainage. It also planned to conduct an economic survey, but new BLM director Kathleen Clarke shut it down after heavy lobbying by the ranching industry.