When President Lyndon Johnson signed the Wilderness Act, on September 3, 1964, he called it one of the “most far-reaching conservation measures” ever approved. The bill established fifty-four wilderness areas, most in the American West, which, together, encompassed more than nine million acres. As the act famously put it, in these areas “the earth and its community of life” were to remain “untrammeled by man.” Homes, roads, cars, and even bicycles would therefore be prohibited.
There was, however, a gap in the law, one big enough to drive an earthmover through—or, really, several hundred. To win passage of the measure, which had gone through more than sixty drafts in the course of eight years, its sponsors agreed to a compromise. For the next twenty years, mining claims would still be…