U.S. Geological Survey 19980623 map Helena, MT Montana State Library http://geoinfo.msl.mt.gov/data/DRG/100k http://mslapps.mt.gov/Geographic_Information/Data/DataList/datalist_Details.aspx?did={1C37C4AF-9EF2-42F4-B790-E884CD8285DF} U.S. Geological Survey (USGS) Digital Raster Graphics (DRGs) are scanned, georeferenced images of USGS topographic maps. These original TIFF image files from the USGS include the collar information and are georeferenced to the UTM grid. The publication dates of the USGS quadrangles whose images were used to create this image may be viewed at https://ftpgeoinfo.msl.mt.gov/Documents/Maps/Individual/20031209_98_q100dates.gif. This document is a summary of all the original UTM 1:100,000 scale DRG files on the Montana State Library web site. Each individual DRG file comes with an accompanying metadata document that gives the quadrangle name and date. Each file is in UTM coordinates. Quadrangles west of the 114th meridian are in zone 11, quads between the 114th and 108th meridians are in zone 12, and quads east of the 108th meridian are in zone 13. We received these map images in 1998. The files have not been updated since that time, and many of the maps are more than 50 years old. Newer versions of many of these images may be available from the USGS. 1970 1995 Publication Date Complete -116.57 -103.45 49.08 43.76 ISO 19115 Topic Category imageryBaseMapsEarthCover digital raster graphic DRG topographic map Montana Wyoming Idaho None The Montana State Library provides this product/service for informational purposes only. The Library did not produce it for, nor is it suitable for legal, engineering, or surveying purposes. Consumers of this information should review or consult the primary data and information sources to ascertain the viability of the information for their purposes. The Library provides these data in good faith but does not represent or warrant its accuracy, adequacy, or completeness. In no event shall the Library be liable for any incorrect results or analysis; any direct, indirect, special, or consequential damages to any party; or any lost profits arising out of or in connection with the use or the inability to use the data or the services provided. The Library makes these data and services available as a convenience to the public, and for no other purpose. The Library reserves the right to change or revise published data and/or services at any time. Montana State Library mailing address

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Helena Montana 59620-1800 406-444-5354 Montana Relay 711 406-444-0266 geoinfo@mt.gov http://docs.msl.mt.gov/geoinfo/Images/Metadata/drg100.gif https://ftpgeoinfo.msl.mt.gov/Documents/Maps/Individual/20031209_98_q100dates.gif Image showing publication dates of the USGS quadrangles that were used to create the map images. Most DRGs in Montana were produced through and Innovative Partnership agreement between the Land Information Technology Company, Ltd., of Aurora, CO and the USGS. A DRG is an 8-bit color image that employs a color pallette to ensure uniform colors throughout a particular DRG series. All DRG's within a series must have the same RGB value. DRGs are faithfully reproduced digital images of the original source maps. Some differences may be detected between the source graphics used and the DRGs due to the RGB values assigned that particular color. The intent is to re-create those colors as near as possible. Data completeness for DRG files reflect content of the source graphics. Features may have been eliminated or generalized on the source graphics due to scale and legibility constraints. For information on collection and inclusion criteria, see U.S. Geological Survey, 1994, Standards for 1:100,000-Scale Digital Line Graphs and Quadrangle Maps: National Mapping Program Technical Instructions and U.S. Geological Survey, 1994, Standards for Digital Line Graphs: National Mapping Program. Approximate horizontal accuracy is 50 meters, assuming source data meets National Map Accuracy Standards. Vertical accuracy is approximately one-half of the mapped contour interval. National Mapping Division U.S. Geological Survey 1970 map Reston, VA U.S. Geological Survey 100000 paper 1970 1996 Publication Date D100 The data set is an image of this source. The production procedures, instrumentation, hardware, and software used in the collection of standard DRG products vary depending on systems used at the contract, cooperator or USGS production sites. The majority of DRG data sets are acquired through government contract. The process step describes, in general, the process used in the production of standard DRG data sets. 1. Production of a DRG begins with the scanning of a paper 60x30-minute topographic map (map1) on a high-resolution scanner. Scanning resolutions range from 500 - 1000 dpi with the output file running between 160-300 mb. 2. Removal of screens (descreening) and color quantization to reduce the number of colors also takes place during the scanning phase. 3. The raw scan file is then transformed and georeferenced using UTM coordinates of the sixteen 2.5-minute grid ticks, which are obtained using the in-house produced program COORDAT and stored in a ground control file. Those sixteen 2.5-minute ticks are interactively visited and assigned their respective UTM coordinates. USGS program XSHAPES4 then performs a piecewise linear rubber sheet transformation. 4. An output resolution of 10.16 meters is chosen in order to resample the file to 250 dpi. 5. The image file is converted to a TIFF and further reduced by converting the file to a run length encoding Packbits compression(type 32773). 6. The color palette of the compressed DRG is then standardized by replacing the original RGB values assigned during the scanning process with standard RGB value combinations using the in-house produced TIFFREMAP program. 7. Prior to archiving the DRG undergoes the following quality assurance procedures: a. The color index values of each DRG are checked to ensure the RGB combinations are consistent with the standardized color palette. b. All DRG files are inspected to ensure that they are geometrically consistent with normal map presentation. c. Selected DRG's are checked to ensure that data elements in the DRG metadata file correspond to the map collar information and to the information in the associated image file. d. Selected DRG's are checked for georeferencing accuracy by comparing the book value of latitude and longitude tick marks with corresponding tick intersections in the DRG image. e. Transformations are checked on selected DRG's by comparing the positions of well defined points, such as UTM grid intersections in the graphic product, with the corresponding image points in the DRG. USGS DRG production specifications are available on request from the National Mapping Division and Mid-Continent Mapping Center by contacting: Rolla-ESIC U.S. Geological Survey 1400 Independence Rd., MS231 Rolla, MO 65401-2602 Phone (573)308-3500 Facsimile (573)308-3615 E-mail to mcmcesic@usgs.gov World Wide Web: http://mcmcweb.er.usgs.gov/drg/ D100 1996 fin Raster Pixel 8000 5500 Universal Transverse Mercator 12 0.9996 -111.0 0.0 500000 0.0 row and column 10.16 10.16 meters North American Datum of 1927 Clarke 1866 6378206.4 294.98 NGVD29 100 FEET Images of contours Each raster entity or pixel contains a color index from 0 through 12 referencing a color palette of RGB values from 0 through 255 in which the standard colors used in the DRG are defined. USGS DRG Color Palette Number Color Red Green Blue 0 Black 0 0 0 1 White 255 255 255 2 Blue 0 151 164 3 Red 203 0 23 4 Brown 131 66 37 5 Green 201 234 157 6 Purple 137 51 128 7 Yellow 255 234 0 8 Light Blue 167 226 226 9 Light Red 255 184 184 10 Light Purple 218 179 214 11 Light Grey 209 209 209 12 Light Brown 207 164 142 Draft Standards for Digital Raster Graphic. Montana State Library mailing address

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Helena MT 59620-1800 406-444-5354 Montana Relay 711 406-444-0266 geoinfo@mt.gov Downloadable Data The Montana State Library provides this product/service for informational purposes only. The Library did not produce it for, nor is it suitable for legal, engineering, or surveying purposes. Consumers of this information should review or consult the primary data and information sources to ascertain the viability of the information for their purposes. The Library provides these data in good faith but does not represent or warrant its accuracy, adequacy, or completeness. In no event shall the Library be liable for any incorrect results or analysis; any direct, indirect, special, or consequential damages to any party; or any lost profits arising out of or in connection with the use or the inability to use the data or the services provided. The Library makes these data and services available as a convenience to the public, and for no other purpose. The Library reserves the right to change or revise published data and/or services at any time. TIFF http://geoinfo.msl.mt.gov/data/DRG/100k 20160823 20000105 Montana State Library mailing address

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Helena Montana 59620-1800 406-444-5354 Montana Relay 711 406-444-0266 geoinfo@mt.gov FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998 {4888821F-127E-4890-9636-8CB1BFDB2E50}