U.S. Supreme Court Halts the Construction of the High Mountain Sheep Dam


By Taylor Bailey::


“Great Falls of Snake River, Idaho Territory,” by artist Thomas Moran (1876). Source: Library of Congress.

Water is a constant theme in Western history. Environmental historian Donald Worster, in his classic book Rivers of Empire: Water, Aridity, and the Growth of the American West, has written that history of the American West is marked by how Westerners dammed and diverted waterways for human use in a predominantly arid environment. The Snake River is no exception. Fed by the snowy peaks of the Rocky Mountains, the Snake begins in western Wyoming, crosses through southern Idaho, forms the western boundary between Idaho and Oregon, all before entering Washington state and joining the Columbia river.

On June 5, 1967, the U.S. Supreme Court issued its landmark decision in Udall v. Federal Power Commission, which temporarily prevented the High Mountain Sheep Dam from being being built in the Hells Canyon region of the Snake River, located in western Idaho. Although the Supreme Court did not permanently prevent the construction of a dam at the High Mountain Sheep site, this was the first time the Court had stipulated that the Federal Power Commission, which was a five person commission of presidentially appointed, Senate confirmed members who were tasked with regulating hydroelectric projects under the Federal Water Power Act, must consider the ‘public interest’ in their decisions.

At the time, the Idaho Power Company had already constructed two dams in the Hells Canyon region, the Brownlee Dam (completed 1958) and the Oxbow Dam (completed 1961). A third–the Hells Canyon Dam–was near completion. Together, these dams represented the Hells Canyon Project, which was approved by the Federal Power Commission in 1955. Now, two power companies, the Pacific Northwest Power Company and the Washington Public Power Supply System, sought permits from the Federal Power Commission to dam the remaining downriver stretch of the Snake River.

Pacific Northwest Power and Washington Public Power competed for permits to develop dams in the nearly the same location. Pacific Northwest had chosen the High Mountain Sheep Site, a mile upstream from the confluence of the Snake and Salmon rivers. Washington Public Power wanted to build at a dam directly downstream of the confluence, called the Nez Perce Site. The Federal Power Commission denied Washington Public Power their permit due to concerns about the negative impact the dam would have on fish populations by blocking them from both the Snake and Salmon rivers. When the commission denied the Nez Perce site permit, Washington Public Power petitioned that they should be granted preference to develop the High Mountain Sheep instead of Pacific Northwest Power because it represented public utilities, not private ones.

The commission sided with Pacific Northwest Power, and granted them the permit. But the Department of the Interior had concerns about the proposed dam, too, and thought it should be a federal project. So Secretary of the Interior Stewart Udall and Washington Public Power appealed to the district court, but lost. They then appealed to the Supreme Court on the grounds that the appeals court had misinterpreted the “public preference” clause of the Federal Water Power Act, which allegedly gave preference to public hydropower development over private corporations. The Supreme Court took the case.

Ultimately, neither Washington Public Power nor the federal government won the rights to build the dam as result of the Supreme Court decision. In the majority opinion written by Justice William O. Douglas, the Court returned the case to the Federal Power Commission, instructing them to rehear proceedings regarding the High Mountain Sheep Dam. The Court stipulated that the commission must simply not decide who is best suited to build the dam, but whether or not the dam should be built in the first place. Justice Douglas called this the ‘public interest test.’ That is, the commission must consider the public interest in conserving wild rivers and wilderness, fish stocks for commercial and recreational purposes, and the protection of wildlife. For the moment, construction of the High Mountain Sheep Dam was halted.

This decision was made at the cusp of the rise of the environmental movement in the United States. Shortly after the ruling, environmental advocacy groups such as the Sierra Club and the Wilderness Society allied with state governments in Washington, Oregon, and Idaho to prevent the High Mountain Sheep Dam from being built in the interest of preserving its scenic beauty. In 1975, President Gerald Ford signed a law prohibiting the construction of the dam and created the Hells Canyon National Recreation Area.

Until Udall v. Federal Power Commission, the commission made decisions about proposed dam projects from a utilitarian perspectivewho could best construct the dam, preserve salmon runs, and provide power needs. From this point forward, the commission would have to weigh another considerationthe public interest in building the dam. The High Mountain Sheep case represents a turning point in the interpretation of federal environmental law. Public interest in conserving nature demanded that potential ecological ramifications of future hydroelectric projects be considered.

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Music used
Red Hot Chili Peppers, “Feasting on the Flowers”

Taylor Bailey, Project Manager
Tanya Monthey, fact checker and editor