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BACKGROUND • In 1967, the Denver and Portland Service Center personnel were assigned the development of an erosion inventory procedure to be applied to 160 million acres of public lands during the subsequent 5-to-10 year period. Essentially, no quantitative data were in existence nor did the Bureaus have the resources to obtain personnel (in the GS-3 to GS-9 grade levels) to make estimates of current erosion activity. These estimates were based on soil surface features visible to field technicians and reworded as numerical values [hat were used as a basis for five narrative erosion classes. The procedure was utilized on 135 million acres of and and semiarid land from 1971 to 1978, or 2,264 watershed areas. Numerical values describing the erosion condition classes were called Soil Surface Factors (SSF). The factors varied from a value of 1 to 100 and were obtained with an accuracy between inventory party members of + 5 of the actual value. In February 1977, a directive was issued to develop a coordinated site inventory procedure to gather baseline soils, vegetation and wildlife data to provide the basic inventory to implement the organic actl, range management planning, and preparation of environmental state- ments. This directive provided for developing an operational Site Inventory Method (SIM) for field season 1978 after field-testing in the Worland and Las Cruces districts. • Due to projected costs and manpower requirements, the SIM procedure was revised to provide for the present Soil-Vegetation (Ecological Site) Inventory Method (SVIM). It was recommended by the SZM--- Vegetation Allocation Task Force to delete the SSF determination from the procedure since moat (84 percent) of the public lands had a Phase 1, Watershed Conservation and Development (WC6D) inventory. A position paper by the author in January 1978 submitted the following rationale for continuance of SSF determination in future inventories: 1. An erosion condition asessment is necessary to correlate with soil properties and ground cover to determine of ecological range condition (seral stage) for each site write-up area. 2. SSF is needed as an index of changes in erosion activity over time with alternative intensities of management and land treatment. 3. Erosion condition data is used as an index to measure apparent trend. 1Public Law 94-579 - Federal Land Management and Public Administra- tion Act, Section 201, Inventory and Identification. • 3