This dataset contains all National Forest Inventoried Roadless Areas (IRAs) for the lower 48 states, including Puerto Rico. Alaska is maintained separately. The IRA data was originally submitted to GSTC by all national forests through their Regional Offices for the Forest Service's Roadless Area Conservation Initiative. The data was consolidated at the GSTC and used in the Draft Environment Impact Statement. Between the draft and final stages of the Environmental Impact Statement, the data was updated by the forests to reflect any corrections to Inventoried Roadless Areas that were based on existing forest plans and administrative record. The data was also supplemented to include Special Designated Area information and to include Inventoried Roadless Areas within Special Designated Areas. The data was resubmitted to the GSTC on July 21, 2000 for consolidation and the completed coverage was used in the Roadless Area Conservation Final Environmental Impact Statement. On October 15, 2002, the Gallatin National Forest submitted a technical correction to the Inventoried Roadless Area GIS database. A portion of the original GIS data was corrected to match the 1999 IRA maps that are part of the forest administrative record. IRAs are based on completed forest plans, forest plans in revision where the agency has established an inventory (this information should be available in Appendix C of most forest plans), or other assessments that are completed and adopted by the agency. RARE II information was used in cases where a forest does not have a more current roadless inventory, which was established using RARE II information. Only the attributes Region, Forest, State, Name, and Category were retained from the original dataset. The Conservation Biology Institute added Acres and HA, which were calculated using the CONUS Albers Equal Area Projection.