Management Areas can be separated into 5 categories -- A, B, C, D and E. Category "A" MAs have primary resource emphases other than timber production; regulated timber harvest is not allowed, but timber salvage may in some cases be considered. Category "B" MAs also have primary resource emphases other than timber production, but regulated timber production is planned. The Category "C" MA (i.e. C1 Timber Emphasis) has timber production as the primary emphasis and a variety of secondary other resource emphases. The "D-Series" Category represents MAs within the Bull Run Watershed Management Unit. Production of high quality water is the primary resource emphasis but a variety of other resource values are realized as well. The "D-Series" MAs are intended to be consistent with the Bull Run Watershed Environmental Impact Statement (1979). Columbia River Gorge National Scenic Area is represented by an "E-Series" of MAs; scenic quality and recreation are primary emphases, with other resource values also recognized.