As given in “Sutter's Mill Question..” at: http://six.pairlist.net/pipermail/meteorite-list/2012-May/084908.html Dennis Miller asked:
“For my personal edification, what is the name of the USGA Quadrangle map you are using. I need to start another strewn field map, with itty bitty dots, so far. 1. freewu2000 at yahoo.com replied: “In Placerville I picked up 15 min topomaps named Coloma. Also Pilot Hill to the west for where the big one are speculated to be.” and 2. Dennis Miller replied: “Thanks for the map information. I did go to USGS and ordered Coloma and Pilot Hill topos. The Coloma (#328961) map is a 2012 aerial map.” For GIS-minded people, free georeferenced 1:24,000 scale topographic map mosaic for all of El Dorado County, California can be downloaded from the USDA Natural Resource Conservation Service Geospatial Datagateway at http://datagateway.nrcs.usda.gov/ . For thedownloading the to the “Order by County/Counties” at: http://datagateway.nrcs.usda.gov/GDGOrder.aspx . From the above link a person can get free 1. Digital Raster Graphic Topographic Map County Mosaic by the NRCS, 2. and 2. high-resolution aerial imagery for 2009 and 2010. Both of these are georeferenced. Finally, National Elevation Dataset, 3-meter resolution, is available for download. Individual georeferenced digital raster topographic maps are available for free from the Cal-Atlas geospatial clearinghouse at http://atlas.ca.gov/download.html and the Cal-Atlas: Imagery Download Tool at http://atlas.ca.gov/imagerySearch.html . For finding the topographic maps check /choose the DRG data layer in the "Download Tool" menu Coloma 1:24,000 topographic map is “DRG O Series o38120g8.” Pilot Hill 1:24,000 topographic map is “DRG O Series o38121g1.” There is a choice of either collared (untrimmed) or collarless (trimmed) DRGs (Digital Raster Graphics) for the topographic maps. I have loaded the individual DRGs for my field areas into the company Ipad and used available apps to keep track of my location as a blue dot on the DRG base I moved around doing fieldwork. The same can be done with many GPS units or other portable electronics. Best wishes, Paul h. ______________________________________________ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list [email protected] http://six.pairlist.net/mailman/listinfo/meteorite-list
