Andrew Y. Morita Steven K. Predmore Unpublished material Unknown map http://water.usgs.gov/lookup/getspatial?sgpwa_drg27_image This Digital Raster Graphic (DRG) was created using scanned U.S. Geological Survey 7.5-minute 1 to 24,000 scale maps georeferenced in Universal Transverse Mercator (UTM) grid. DRGs can be acquired with or without collar information for use in Geographic Information System (GIS) environment. Collarless DRGs can be edge matched creating a continuous collection of topographic maps. In a GIS environment, a DRG can be used as a source or background layer to perform quality assurance on other digital products. DRGs can also be used as a source for the collection and revision of Digital Line Graphs (DLGs), Digital Elevation Models (DEMs), or Digital Orthophoto Quadrangles (DOQs). For this dataset, fifteen 7.5-minute 1 to 24,000 scale collarless DRGs were used to produce a hydrid digital file. The DRGs were edge matched, georeferenced, and re-projected in UTM coordinates to provide an image of the San Gorgonio Pass and surrounding area in Riverside County, California. 20011101 Source map Complete None planned -117.25110021 -116.62335041 34.12533042 33.749428 None Topographical Maps Topo DRG Land Surface San Gorgonio Image Tiff inlandWaters None San Gorgonio Pass Riverside County California United States none none Allen H. Christensen U.S. Geological Survey Hydrologist (mailing and physical address)

U.S. Geological Survey, WRD. San Diego Project Office 5735 Kearny Villa Road, Suite O.

San Diego CA 92123 USA 1-888-275-8747 (858) 637-9201 ahchrist@usgs.gov Contact via email. http://water.usgs.gov/GIS/browse/sgpwa_drg27.jpg Representation of the data set jpg Windows_NT, 5.0, Intel ARC/INFO version 8.1 n/a A Digital Raster Graphic (DRG) is a scanned digital image of the original source map. Completeness in data solely reflect the source map. Generalizations and deletions of some features may occur due to scale and legibility constraints. The datum of the map is consistent with standard 7.5 minute USGS topographical maps. U.S. Geological Survey, EROS Data Center 19981101 map Sioux Falls U.S. Geological Survey EROS Data Center The source for the DRGs are the standard quadrangle format for the USGS topographic maps as described in the Federal Geographic Data Committee products manual. 24,000 paper 19880701 19880701 Ground Condition USGS Topo n/a The original projection parameters for the .tif (tagged image file format) image were UTM, NAD27, Units meters, Zone 11, with a Y-shift of -3,5000,000. ArcInfo command "imagegrid" converted the .tif image into grid format and then re-projected to UTM, NAD27, Units meters, Zone 11, with a negative Y-shift equal to zero. The final processing step was convert the re-projected grid into a geographically referenced image using ArcInfo command "gridimage" to .tif format. This tif was converted to grid using the ArcInfo command "imagegrid" for reprojection. The image was originally projected in UTM zone 11, meters, NAD27, yshift -3,500,000. After the grid was reprojected, its current projection is now UTM zone 11, meters, NAD27 yshift 0. The final process was to convert the reprojected grid into a geographically referenced image. ArcInfo command "gridimage" was used to convert the image into .tif format. 20011101 Andrew Y. Morita U.S. Geological Survey Geographer mailing and physical address

U.S. Geological Survey, WRD. San Diego Project Office 5735 Kearny Villa Road, Suite O.

San Diego CA 92123 USA 1-888-275-8747 (858) 637-9201 amorita@usgs.gov Contact via email. U.S. Geological Survey Ask USGS - Water Webserver Team mailing

445 National Center

Reston VA 20192 1-888-275-8747 (1-888-ASK-USGS) http://answers.usgs.gov/cgi-bin/gsanswers?pemail=h2oteam&subject=GIS+Dataset+sgpwa_drg27_image Although this data set has been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data and related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of this data, software, or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Other Full coverage zipped 1 http://water.usgs.gov/GIS/dsdl/sgpwadrg27.tif.gz Other Full coverage 1 http://water.usgs.gov/GIS/dsdl/sgpwadrg27.tfw None. This dataset is provided by USGS as a public service. 20041108 U.S. Geological Survey Ask USGS -- Water Webserver Team mailing

445 National Center

Reston VA 20192 1-888-275-8747 (1-888-ASK-USGS) http://answers.usgs.gov/cgi-bin/gsanswers?pemail=h2oteam&subject=GIS+Dataset+sgpwa_drg27_image FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998