Inventoried Roadless Areas are a group of United States Forest Service lands that have been identified by government reviews as lands without existing roads that could be suitable for roadless area conservation as wilderness or other non-standard protections. The Inventoried Roadless areas include approximately 60,000,000 acres (240,000 km2) of land in 40 states and Puerto Rico. Most of these lands are in the western portion of the lower 48 states and Alaska. Idaho alone contains over 9 million acres (36,000 km2) of inventoried roadless areas. The inventoried roadless areas range from large unroaded areas with wilderness characteristics to small tracts of land that are immediately adjacent to wilderness areas, parks and other protected lands.
The first review of Forest Service roadless lands was started in 1967 after the creation of the Wilderness Act by Congress in 1964. This effort was called the “Roadless Area Review and Evaluation” or “RARE I”, and culminated in 1972 with a finding that 12,300,000 acres (50,000 km2) that were suitable to be designated as wilderness. The RARE I recommendations were abandoned by the Forest Service after courts ruled that the agency had not sufficiently complied with the regulations of the National Environmental Policy Act (NEPA). A second roadless inventory, RARE II, was initiated in 1977, which culminated in a recommendation of wilderness designation for 15,000,000 acres (61,000 km2) of national forest land and further study for another 10,800,000 acres (44,000 km2). This set of recommendations was also quickly challenged in the courts and largely voided as a result.
The most recent review of inventoried roadless areas began in 1998 under the oversight of Michael Dombeck, then head of the US Forest Service. This review was finished in 2000 and culminated in a set of Forest Service regulations in 2001 that are collectively known as the Roadless Rule. The Roadless Rule of 2001 is certainly the most far-reaching conservation action taken by the federal government since the Wilderness Act of 1964. The rule does not specifically protect roadless areas from development nor does it strictly prohibit multiple use activities on these lands. Specifically, the rule was aimed at controlling the amount of road-building activities undertaken by the forest service, which has more miles of roads under its control than the US Interstate Highway System.