He played a major role in the enactment of the Hells Canyon National Recreation Area Act, which protected scenic Hells Canyon, the deepest river gorge in North America, by making it into a National Recreation Area on the borders of northeastern Oregon and western Idaho. Packwood sponsored the bill, and was credited with becoming "a genuine leader in the preservation battle" in Congress and in the end, second only to the idea's originator "the single most important individual in the history of Hells Canyon preservation". Environmentalists also praised his advocacy of solar energy, returnable bottles, and bike paths.