Situated among the North Cascade Mountains of Washington State, in the Glacier Peak Wilderness Area, Miners Ridge contains vast quantities of copper. Kennecott Copper Corporation's plan to develop an open-pit mine there was, when announced in 1966, the first test of the mining provision of the Wilderness Act passed by Congress in 1964. The battle over the proposed "Open Pit, Big Enough to Be Seen from the Moon," as activists called it, drew the attention...