Data Source Source Description Resolution         Sediment   Soils on U.S. Forest Service land USFS (1999) U.S. Forest Service (Gifford Pinchot National Forest) forest soils and soil map units 1:15,840 Soils on state, county, and private lands NRCS (2003–2004) USDA Natural Resources Conservation Service Soil Survey Geographic Database (SSURGO) for Cowlitz, Clark, and Skamania Counties 1:250,000   Hydrology   Stream hydrography (routed) SSHIAP (2004) Salmon and Steelhead Habitat Inventory and Assessment Program (SSHIAP) unpublished spatial data on hydrology and stream conditions (1:24,000) for Watershed Inventory Area (WRIA) 27 1:24,000 Stream hydrography (drainage enforced and routed) Miller (2003) Routed, cleaned and attributed stream hydrography generated to match SSHIAP hydrography following methods by Miller (2003); Generated to facilitate sediment routing and estimation of channel characteristics 1:24,000 6th Field Hydrologic Unit boundaries (HUCs) BLM (2002) Regional Ecosystem Office (REO) Hydrologic Unit Boundaries for Oregon, Washington, and California, Portland, Oregon, USA 1:24,000 7th Field Hydrologic Unit boundaries (HUCs) Lewis County (2000) Lewis County GIS (2001) data on 7th field hydrologic boundaries for the Lewis watershed unknown   Topography and Geology   Surficial geology WDNR (2003) Washington State Department of Natural Resources (WDNR) classification of geologic map units according to major lithology (WDNR 2003) 1:100,000 Slope stability WDNR (2000) WDNR predictive data layer of shallow-rapid slope stability from calibrated GIS-based models. Updated for the Lewis watershed using methods by Shaw and Vageois (1999) 1:24,000 Elevation USGS (2003) USGS 10 m drainage enforced Digital Elevation Model (DEM). Multiple DEMs mosaicked, and used to generate hydrographic stream layer, to associate streams with topographic features, and to generate lateral hillslope watersheds for stream segments 1:24,000 Hillslope USGS (2003) Hillslope gradient calculated for every 10-m gridcell in the mosaicked 10-m drainage enforced DEM, using ARC/INFO 1:24,000   Barriers   SSHIAP barriers WDFW (2004) Salmon and Steelhead Habitat Inventory and Assessment Program (SSHIAP) unpublished data on fish passage barriers (1:24,000) for Watershed Inventory Area (WRIA) 27 1:24,000 Dams BPA (2001) Bonneville Power Administration (BPA) dams and possible hydroelectric development sites (BPA 2001); Original source database converted to a spatial datalayer 1:100,000   Political   Regional ownership ICBEMP (1995) Interior Columbia Basin Ecosystem Management (ICBEMP) regional land ownership 1:100,000 Parcel ownership Clark County (2004) Land ownership, parcel boundaries, and land use for Clark County 1:24,000 Parcel ownership WDNR (2005) Land ownership, parcel boundaries, and land use statistics for Clark, Cowlitz, and Skamania Counties 1:24,000 County ownership CommEn Space Washington Protected Lands Database (PLDB 2004, which includes spatial location and conservation status for private and public lands    - Urban growth Clark County (2004) Urban growth boundary for Clark County    - Land use Clark County (2004) Comprehensive plan and land use/zoning for Clark County    -   Vegetation   Land and forest cover IVMP (2001) Interagency Vegetation Mapping Project, Western Cascades (Version 2.0) and Western Lowlands (Version 1.0) Spatial Data 1996 (BLM 2001) 30 m National Land Cover Data USGS (1999) USGS classification of land cover data from LANDSAT TM satellite imagery (level 2). Generated by USGS using Anderson et al. (1976) protocols. 30 m   Fish Distribution   Fish distribution WDFW (2004) Washington Department of Fish and Wildlife (WDFW) Salmon and Steelhead Habitat Inventory and Assessment Program (SSHIAP) data on fish distribution for Watershed Inventory Area (WRIA) 27 1:24,000   Transportation   Roads GP (1995) Forest roads and associated attributes 1:24,000 Roads WDNR (2005) WDNR transportation data layer of roads, railroad, and other land and water transportation routes within Clark, Cowlitz, and Skamania Counties 1:24,000