Hells Canyon: The Deepest Gorge in North America

Hells Canyon is the deepest river gorge in North America. The Snake River at the bottom sits at about one thousand four hundred feet above sea level. The Seven Devils Mountains on the Idaho side rise to nearly nine thousand feet. The vertical relief, measured from river to rim, reaches eight thousand and sixty-one feet. The Grand Canyon, for reference, is about a mile deep, roughly five thousand two hundred eighty feet.

Hells Canyon is administered jointly by the Wallowa-Whitman National Forest on the Oregon side and the Payette and Nez Perce-Clearwater National Forests on the Idaho side. The Hells Canyon National Recreation Area, designated in nineteen seventy-five, encompasses more than six hundred fifty thousand acres and includes two hundred miles of Wild and Scenic river corridor on the Snake.

The canyon was formed by the Snake River cutting through a series of uplifted basalt plateaus over millions of years. The basalt, in places more than fifteen thousand feet thick, accumulated from ancient lava floods that covered much of the Columbia Plateau. The river cut through it as the land rose.

Nez Perce people lived in the canyon country for thousands of years. The canyon walls provided shelter from the harsh plateau winters, the river provided salmon and lamprey, and the terraces supported camas and biscuitroot. The petroglyphs left on the canyon walls are the documented evidence of occupation that the written record does not improve upon.

Three dams block the Snake in the canyon, Oxbow, Brownlee, and Hells Canyon dams, built between nineteen fifty-eight and nineteen sixty-seven. They generate power and block every salmon that would have run above them. The Idaho Power Company, which owns the dams, holds the federal operating license. The operating license comes up for renewal.