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.