Acreages within Fire Condition classes 1, 2, & 3 and Fire Regime classes 2 & 3 (lumped) stratified by Inventoried Roadless Area Category
Fire condition class and fire regime data were only available for the lower 48 states.  This table does not include acreages in Alaska or Puerto Rico.  All acreage figures are rounded to the nearest 1,000.
IRA Category	Fire Condition Class	Fire Regime	Acres (1,000)
1B	1	0-35 yrs; Low Severity & Stand Replacement	664
1B	2	0-35 yrs; Low Severity & Stand Replacement	1,828
1B	3	0-35 yrs; Low Severity & Stand Replacement	1,223
1B-1	1	0-35 yrs; Low Severity & Stand Replacement	91
1B-1	2	0-35 yrs; Low Severity & Stand Replacement	198
1B-1	3	0-35 yrs; Low Severity & Stand Replacement	55
1C	1	0-35 yrs; Low Severity & Stand Replacement	2,253
1C	2	0-35 yrs; Low Severity & Stand Replacement	4,793
1C	3	0-35 yrs; Low Severity & Stand Replacement	2,437
Definitions of Categories of Inventoried Roadless Areas
1B	Inventoried roadless area where road construction or reconstruction is not allowed
1B-1	Inventoried roadless area where road construction or reconstruction is not allowed, and the forest plan recommends as wilderness
1C	Inventoried roadless area where road construction or reconstruction is allowed
Definitions of Fire Condition Classes
1	Forested areas with an historically short fire return interval usually have frequent fires of low intensity
2	One or more fire return intervals have been missed, possibly resulting in increased fire sizes and intensities and decreased landscape mosaics and diversity
3	Multiple fire return intervals have been missed resulting in dramatic departure from historical conditions