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This page last updated: 04/09/2007
Metadata created using Minnesota Geographic Metadata Guidelines
| Originator | United States Geological Survey (USGS) - National Mapping Division |
| Abstract | The DLG HYDROGRAPHY file is a GIS layer originally created by the United States Geological Survey to represent all surface hydrologic features appearing on the USGS 1:100,000 map sheet series. This version was converted to ARC/INFO by the Land Management Information Center and edge-matched across map sheet boundaries. In addition, LMIC made some corrections to feature identification, and added state water identifiers to lakes, wetlands, and river features. LMIC modifications to the files originally obtained from the United States Geological Survey include: 1) Conversion from Digital Line Graph format to ARC/INFO format; 2) Edge-matching of all 1:24,000 sheets which made up the 1:100,000 sheets; 3) Changing of arc directions so that all stream features flowed in a downstream direction; 4) Addition of the DNR Common Stream and Watershed Number (CSAW#) to major streams; 5) Addition of the DNR Division of Waters Lake Number to all lakes and wetlands on the file which were labeled as protected water features on the DNR Protected Waters Inventory county map series. Although DNR Division of Lake numbers were added to the file, this coverage does NOT constitute an official state Protected Waters Inventory layer: the information is not complete. |
| Browse Graphic | none available |
| Time Period of Content Date | |
| Currentness Reference | DLG data were automated from the most recent USGS sources available at the time. No specific study has been undertaken to determine the range of dates associated with the maps used to create the data set. Some representations extend back 20 years or more. The files were converted to Arc/INFO in 1989. Division of Waters Lake Number tagging was done using the official DNR set of Protected Waters Inventory county maps. CSAW river numbering was done using the 1:24,000 USGS base map series stored at DNR which as the watershed boundaries delineated and numbered on mylar overlays, and the CSAW number for each minor watershed identified. |
| Access Constraints | None |
| Use Constraints | Use should be consistent with the source and scale of the originating maps. Division of Waters Lake numbers were attached to lake and wetland polygons where identifiable, using the DNR Protected Waters Inventory County Map Series as a guide. However, since all lake and wetland polygons on the DNR maps were not on the 1:100,000 GIS file, this does NOT constitute a complete, official, Protected Waters Inventory layer. Although there were a couple of passes at adding and reviewing identifiers, both the original USGS feature type code and the DOW lake numbers and CSAW numbers should be reviewed before final map presentation. Redistribution Conditions: In obtaining these data from LMIC, it is understood that you and/or your organization have the right to use them for any internal purpose. If you modify them, you should document those changes in a metadata record that should accompany all redistributed data. If you transmit or provide these data in any form to another user, the data MUST be accompanied by a copy of this disclaimer and all documentation provided with the original data set including the full metadata record. |
| Distributor Organization | Minnesota Land Management Information Center (LMIC) |
| Ordering Instructions | Contact distributor |
| Online Linkage | none available |
Go to Section:
1. Identification Information
2. Data Quality Information
3. Spatial Data Organization Information
4. Spatial Reference Information
5. Entity and Attribute Information
6. Distribution Information
7. Metadata Reference Information
| Section 1 | Identification Information | Top of page | ||
| Originator | United States Geological Survey (USGS) - National Mapping Division | |||
| Title | USGS 1:100,000 Digital Line Graph Hydrography Layer, customized for Minnesota by LMIC | |||
| Abstract | The DLG HYDROGRAPHY file is a GIS layer originally created by the United States Geological Survey to represent all surface hydrologic features appearing on the USGS 1:100,000 map sheet series. This version was converted to ARC/INFO by the Land Management Information Center and edge-matched across map sheet boundaries. In addition, LMIC made some corrections to feature identification, and added state water identifiers to lakes, wetlands, and river features. LMIC modifications to the files originally obtained from the United States Geological Survey include: 1) Conversion from Digital Line Graph format to ARC/INFO format; 2) Edge-matching of all 1:24,000 sheets which made up the 1:100,000 sheets; 3) Changing of arc directions so that all stream features flowed in a downstream direction; 4) Addition of the DNR Common Stream and Watershed Number (CSAW#) to major streams; 5) Addition of the DNR Division of Waters Lake Number to all lakes and wetlands on the file which were labeled as protected water features on the DNR Protected Waters Inventory county map series. Although DNR Division of Lake numbers were added to the file, this coverage does NOT constitute an official state Protected Waters Inventory layer: the information is not complete. |
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| Purpose | The National Cartographic Information Center (NCIC) distributes digital cartographic data files produced by the USGS as part of the National Mapping Program. The 1:100,00 Digital Line Graph digital files were created as a digital data set associated with the USGS Topographic Map Series. The purpose was to provide complete national coverage, at 1:100,000 scale, for the production of cartographic products, and to support the analytical functions of GIS. All types of features represented on the Map Series are to be represented. Enhancements made by LMIC were made in order to create a Surface Water GIS base layer which was edgematched and contained sufficient identifier information that it could be used to map information related to streams and lakes (such as lake water quality, lake levels, or wild and scenic rivers status) which was collected by government water management agencies. The original edge-matching and ARC/INFO conversion was part of a LMIC data development effort; river and lake ID tagging was done as part of the LMIC Stream Information System development. |
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| Time Period of Content Date | ||||
| Currentness Reference | DLG data were automated from the most recent USGS sources available at the time. No specific study has been undertaken to determine the range of dates associated with the maps used to create the data set. Some representations extend back 20 years or more. The files were converted to Arc/INFO in 1989. Division of Waters Lake Number tagging was done using the official DNR set of Protected Waters Inventory county maps. CSAW river numbering was done using the 1:24,000 USGS base map series stored at DNR which as the watershed boundaries delineated and numbered on mylar overlays, and the CSAW number for each minor watershed identified. | |||
| Progress | Complete | |||
| Maintenance and Update Frequency | None Planned. Several rounds of corrections have been made (see lineage). | |||
| Spatial Extent of Data | State of Minnesota | |||
| Bounding Coordinates | -97.5 -89.0 49.5 43.0 |
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| Place Keywords | Minnesota, Statewide | |||
| Theme Keywords | inlandWaters, Hydrography, Surface Water, Hydrology, Lakes, Rivers, Streams, Wetlands, DNR Division of Waters Lake Numbers, CSAW Stream Numbers | |||
| Theme Keyword Thesaurus | ISO 19115 Topic Category | |||
| Access Constraints | None | |||
| Use Constraints | Use should be consistent with the source and scale of the originating maps. Division of Waters Lake numbers were attached to lake and wetland polygons where identifiable, using the DNR Protected Waters Inventory County Map Series as a guide. However, since all lake and wetland polygons on the DNR maps were not on the 1:100,000 GIS file, this does NOT constitute a complete, official, Protected Waters Inventory layer. Although there were a couple of passes at adding and reviewing identifiers, both the original USGS feature type code and the DOW lake numbers and CSAW numbers should be reviewed before final map presentation. Redistribution Conditions: In obtaining these data from LMIC, it is understood that you and/or your organization have the right to use them for any internal purpose. If you modify them, you should document those changes in a metadata record that should accompany all redistributed data. If you transmit or provide these data in any form to another user, the data MUST be accompanied by a copy of this disclaimer and all documentation provided with the original data set including the full metadata record. |
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| Contact Person Information | Susanne Maeder,
GIS Data Coordinator Minnesota Land Management Information Center (LMIC) 300 Centennial Building; 658 Cedar Street St. Paul, Minnesota 55155 Phone: 651.201.2488 FAX: 651.296.3698 E-mail: susanne.maeder@state.mn.us | |||
| Browse Graphic | none available | |||
| Browse Graphic File Description | ||||
| Associated Data Sets | The Minnesota Department of Natural Resources offers the dlg hydrography data set broken into a streams layer and a lakes layer. These are available at: http://deli.dnr.state.mn.us/metadata/full/dlgstln2.html (streams only) http://deli.dnr.state.mn.us/metadata/full/dlglkpy2.html (lakes & wetlands only) LMIC offers the dlg_hy file as a statewide data set (dlghyne2). See http://www.lmic.state.mn.us/chouse/metadata/dlghyne2.html The DNR Division of Waters lakes list (data table) contains lake identifiers, lake name, area, and protected waters status for all lakes and wetlands enumerated as part of either the DNR Protected Waters Inventory or the 1967 Inventory of Minnesota Lakes (DNR Bulletin 25). This table is available for download. See http://www.lmic.state.mn.us/chouse/metadata/dowlakes.html The CSAW (Common Stream and Watershed Numbering) data tables contain river names and associated watershed information and can be used to associate river names with the CSAW river number on this file. These tables are available for download. See http://www.lmic.state.mn.us/chouse/metadata/csaw.html |
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| Section 2 | Data Quality Information | Top of full metadata | Top of page | |
| Attribute Accuracy | DLG source data has a 98.5 percent corrent accuracy specification. No subsequent tests have been performed following ARC/INFO processing. Water body coding has demonstrated inconsistencies in the reservoir feature type, with some man-made waterbodies being classified as lakes. Stream coding for status of perennial or intermittent has been corrupted as the result of previous data processing errors, rendering this part of the stream classification as unreliable. Although there were a couple of passes at adding and reviewing identifiers, the original USGS feature code (USCLASS), the DNR DOW Lake Number (DOWLKNUM), and the CSAW numbers and associated names should be reviewed for accuracy before final map presentation. | |||
| Logical Consistency | ||||
| Completeness | Data exist statewide. Lake data are consistently complete at a minimum feature size of approximately 5 acres, with mapping to the 2-acre level present in some areas. Some thematic information in the area and line feature classes are inconsistently mapped, and should not be considered complete information categories. These include the following feature types: rapids, gravel pits, canal locks or spillways, crevasses, navigable transportation. As already noted, the file does not constitute a complete Protected Waters Inventory' layer, as many lake or wetland polygons designated as protected waters in Minnesota are not represented on the GIS file. | |||
| Horizontal Positional Accuracy | 51 meters | |||
| Lineage | LMIC modifications to the files originally obtained from the United States Geological Survey include: 1) Conversion from Digital Line Graph format to ARC/INFO format; 2) Edge-matching of all 1:24,000 sheets which made up the 1:100,000 sheets; 3) Changing of arc directions so that all stream features flowed in a downstream direction; 4) Addition of the DNR Common Stream and Watershed Number (CSAW#) to major streams; 5) Addition of the DNR Division of Waters Lake Number to all lakes and wetlands on the file which were labeled as protected water features on the DNR Protected Waters Inventory county map series. 1. Original DLG file creation (United States Geological Survey). Most DLG data is automated from the USGS 1:100,000 scale quadrangle series, although, in some cases, sets of USGS 7.5-minute (1:24,000 scale) were phot-reduced to a scale of 1:100,000 and physically merged into a single source manuscript matching the 1:100,000 map sheet. Each of these maps covers an area of 1 degree longitude by 1/2 degree latitude. USGS digital production relied on an automated scanning/vectorization process. To generalize to the 1:100,000 level, polygons smaller than a certain size and line features smaller than a certain length were dropped from the file. Data was made available by USGS in Digital Line Graph format in 7.5-minute map tiles. For more information on the creation of the original USGS data file, see: US GeoDATA: National Mapping Program Technical Instructions 'Digital Line Graphs from 1:100,000-Scale Maps' Data Users Guide 2 USGS/ National Mapping Division, Reston, VA 1989 See especially Appendix D: DLG Attribute Codes. 'MINOR CODE' corresponds to data field 'USCLASS', and 'DESCRIPTION' identifies the feature type. See also USGS metadata created specifically for this layer. 2. Arc/INFO conversion and edgematching (Land Management Information Center, 1989-1990) LMIC converted the USGS data from DLG to ARC/INFO format, and with the help of cooperators, edgematched the original 7.5-minute file blocks into 30 by 60 minute blocks. The edge-match process followed the convention of working in a checkerboard fashion, holding the linework of every other quad within the 30 by 60-minute block stable, and adjusting the linework on alternate quadrangles to the stable linework. 3. Tagging with DNR Division of Waters lake numbers (Land Management Information Center, 1992-1993). LMIC staff went through the files, one 100k sheet at a time, and added lake, wetland, and stream identifiers in two passes. A series of Arc Macro Language (AML) programs were written to support this effort. In the first pass, DNR Division of Waters lake numbers were added to the file as an attribute. For each 100k map sheet, the polygons features identified by USGS as lakes or wetlands were visually compared with a set of DNR Protected Waters Inventory maps, and the lake number on the map was attached to the appropriate polygons which made up the same lake or wetland on the digital file. (In some portions of the state - the Arrowhead region and portions of the Minnesota River Basin, the project was able to make use of a digital, tagged 1:24,000 lake polygon files. In these areas, this information was used as a background and the lake identifier was carried forward.) If it was unclear from the PWI maps how the lakes were numbered (this was often the case in areas where there were many lakes and where the shape of the lake on the PWI map did not match exactly the shape of the lake on the GIS file), the USGS 1:24,000 topographic maps and the DNR lake number table were used as additional reference material. Polygons were assigned the DOW Lake Number if it was obvious what it should be. If not, these numbering conventions were followed: '888888' - The lake polygon needs to be broken down into multiple polygons in order to assign lake IDs (i.e., the polygon actually comprises more than one lake or wetland). '999999' - Lake polygon is not on Protected Waters Inventory Maps - does not have a number. '995000' - Not sure what lake number to give it. '994000' - A wide spot in a river which appears on the DLG file as an isolated lake polygon. Special conditions: 1. One Protected Waters Inventory basin is represented on the DLG file and the quad map as several open water bodies, ususally surrounded by marsh on the quad and sometimes surrouned by marsh on the DLG file. Solution: tag all DLG basins, and marsh boundary with the appropriate DOWLKNUM. Do NOT digitize in the wetland boundary if it is not already on the DLG file. 2. DLG file contains a lake and an associated marsh. The lake and part of the marsh are designated on DNR PWI maps as a protected water. We don't want to have to split up the marsh polygon. Solution: Apply 50% rule (per DNR Waters). If more than half of the marsh area is designated as part of the Protected Water, tag the marsh and the lake with the DOWLKNUM. If less than half of the marsh area is designated as part of the Protected Water, tag the lake but not the marsh (i.e., lake gets the DOWLKNUM, marsh gets '999999'.) 4. River Numbering Processing (Land Management Information Center, 1992-93) A second pass through the data was used to identify multiple sets of arcs which made up a single river trace, and to assign those river traces with a river ID, the DNR Common Stream and Watershed (CSAW) Number for the river. At the same time, river arcs were 'flipped,' if necessary, so that the direction of every river arc was in the downstream direction. For a river numbering reference, staff used the DNR Division of Waters set of USGS 7.5-minute basemaps, overlayed with a mylar overlay on which DNR delineated and numbered major/minor watersheds and, in addition, recorded the CSAW stream number and basin number for the major river flowing through the minor watershed. Thus, CSAW stream numbers were assigned for the major stream in each of the state's 5600 minor watersheds. Other, auxiliary streams in each minor watershed were not labeled on the DNR basemaps and, therefore, not labeled on the GIS file. 5. Water feature (USCLASS) ID verification (LMIC, 1995) In 1995, LMIC made another pass through the file to identify glaring errors in the water feature (i.e., lake, wetland, river trace,) which were part of the attribute coding original to the file. The errors of concern were those which coded all or portions of lakes or wetlands as non-hydrologic features, or which coded land areas as lake or wetland. Slivers of uncoded features were also a concern. Plots were created at 1:100,000 which shaded the areas of concern. A visual pass was used, comparing the plots to the USGS 1:100,000 base maps, then changing the coding as necessary. 6. Second pass verification of DNR DOW Lake and Wetland numbers (LMIC, 1997). In 1997 LMIC did another review of the lake IDs on the file. Each 100K sheet was brought up digitally, drawn at a workable scale with reference background features such as roads and quad boundaries, and the lake numbers on the file were again compared to the DNR Protected Waters Inventory maps, and corrected where necessary. Of the 70+ 100k sheets revisited, one (Detroit Lakes) had experienced corruption of ID coding, one (Lake Minnewaska) had 60-100 ID coding errors, and another 16 contained anywhere from 2 to 20 ID errors per sheet. |
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| Source Scale Denominator | 100000 | |||
| Section 3 | Spatial Data Organization Information | Top of full metadata | Top of page | |
| Native Data Set Environment | Arc/Info 7.1.1 | |||
| Geographic Reference for Tabular Data | ||||
| Spatial Object Type | Vector | |||
| Vendor Specific Object Types | Polygon, Arc | |||
| Tiling Scheme | 30 by 60-minute tiles | |||
| Section 4 | Spatial Reference Information | Top of full metadata | Top of page | |
| Horizontal Coordinate Scheme | UTM | |||
| Ellipsoid | Clarke 1866 | |||
| Horizontal Datum | NAD27 | |||
| Horizontal Units | Meters | |||
| Distance Resolution | ||||
| UTM Zone Number | 15E | |||
| Section 5 | Entity and Attribute Information | Top of full metadata | Top of page | |
| Entity and Attribute Overview | The data is stored in USGS 30-minute by 60-minute blocks, with attributes as described below. Provided with the data set are the CSAW files (see separate metadata record), which can be used to attach a name to the river number, and the DNR Division of Waters lake list (see separate metadata record), which can be used to attach lake name, lake alternate name, and protected waters status, and shoreland zoning classification information to the coverage. | |||
| Entity and Attribute Detailed Citation | The digital line graph hydrography file is stored as an Arc/INFO NET coverage. DLG-HY.AAT contains the following data fields: DATAFILE NAME: DLG-HY.AAT 28 ITEMS: STARTING IN POSITION 1 COL ITEM NAME WDTH OPUT TYP N.DEC ALTERNATE NAME 1 FNODE# 4 5 B - 5 TNODE# 4 5 B - 9 LPOLY# 4 5 B - 13 RPOLY# 4 5 B - 17 LENGTH 8 18 F 5 25 DLG-HY# 4 5 B - 29 DLG-HY-ID 4 5 B - 33 QUAD 4 4 I - 37 HLINE 6 6 I - 43 USCLASS 6 6 I - 49 FLOW 1 1 I - 50 S1 6 6 N 1 56 S2 6 6 N 1 62 S3 6 6 N 1 68 S4 6 6 N 1 74 S5 6 6 N 1 80 S6 6 6 N 1 86 S7 6 6 N 1 92 S8 6 6 N 1 98 S9 6 6 N 1 104 S10 6 6 N 1 ** REDEFINED ITEMS ** 33 CODE 10 10 I - 50 STREAM-# 60 60 C - DATA FIELD DEFINITIONS: FNODE# -- standard ARC field - from node number TNODE# -- standard ARC field - to node number LPOLY# -- standard ARC field - left polygon number RPLOY# -- standard ARC field - right polygon number LENGTH -- standard ARC field - length of arc in cover units DLG-HY# -- standard ARC field - internal identifier for the arc DLG-HY-ID -- standard arc field - arc identifier QUAD -- LMIC standard USGS 1:24,000 quad number HLINE -- ARC -ID on original file. QUAD + HLINE = original unique ARC identifier before further processing. USCLASS -- field describing feature type - from USGS 'minor' code for the feature.) FLOW -- field originally describing flow condition. No longer used. S1 -- First stream digit in the DNR CSAW numbering scheme S2 -- Second stream digit in CSAW S3 - S10 -- Third through tenth stream digits in CSAW, repectively. *** REDEFINED DATA FIELDS: CODE -- No longer used. STREAM-# -- the full DNR CSAW number, created by concatenating all 10 stream digits, S1 through s10) DLG-HY.PAT contains the following data fields: DATAFILE NAME: DLG-HY.PAT 14 ITEMS: STARTING IN POSITION 1 COL ITEM NAME WDTH OPUT TYP N.DEC ALTERNATE NAME 1 AREA 8 18 F 5 9 PERIMETER 8 18 F 5 17 DLG-HY# 4 5 B - 21 DLG-HY-ID 4 5 B - 25 QUAD 4 4 I - 29 HPOLY 6 6 I - 35 USCLASS 6 6 I - 41 PWI# 6 6 C - ** REDEFINED ITEMS ** 25 CODE 10 10 I - DATA FIELD DEFINITIONS AREA -- standard arc field - area of polygon, in map coverage units, squared PERIMETER -- standard arc field - perimeter of polygon, in map coverage units DLG-HY# -- standard arc field - internal polygon number DLG-HY-ID -- standard arc field - polygon identifier QUAD -- LMIC USGS 1:24,000 quadrangle map number HPOLY -- USCLASS -- field describing feature type - from USGS 'minor' code for the feature PWI# -- the DNR Division of Waters Lake Number (DOW number) for the water feature. Water features with a DOW number are lakes or wetlands. The DOW number is a 6-digit field, where the first 2 digits represent the county number and the last 4 digits represent the unique lake or wetland number within the county.) REDEFINED DATA FIELDS: CODE -- no longer used. USCLASS water feature codes represented in the DLG-HYDRO .AAT or .PAT files include the following: 101 Reservoir, 105 Inundation Area, 106 Fish Hatchery, 107 Industrial Water Impoundment, 109 Sewage Treatment Area, 110 Tailings Pond, 111 Marsh, Wetland, Swamp, Bog, 116 Bay, 200 Shoreline, 201 Manmade Shoreline, 202 Closure Line, 203 Indefinite Limit, 204 Apparent Limit, 400 Rapids, 401 Falls, 402 Gravel Pit or Quarry filled with Water, 406 Dam or Weir, 407 Canal Lock or Sluice Gate, 411 Crevasse, 412 Stream, 414 Ditch or Canal, 415 Aqueduct, 419 Channel in Water Area, 421 Lake or Pond, 605 Right Bank, 606 Left Bank, 610 Intermittent, 612 Submerged or sunken, 616 Navigable, By far, the most common USCLASS designations are 200, 201, 204, 412, 414, 605, 606 or 610 for arcs and 101, 111, 412, or 421 for polygons. |
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| Section 6 | Distribution Information | Top of full metadata | Top of page | |
| Publisher | Minnesota Land Management Information Center (LMIC) | |||
| Publication Date | 1997 | |||
| Contact Person Information | Susanne Maeder GIS Data Coordinator Minnesota Land Management Information Center (LMIC) 300 Centennial Building; 658 Cedar Street St. Paul, Minnesota 55155 Phone: 651.201.2488 FAX: 651.296.3698 E-mail: clearing.house@state.mn.us |
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| Distributor's Data Set Identifier | dlg_hy | |||
| Distribution Liability | Limitations: Although extensive effort has been made to produce error free and complete data, all geographic information has limitations due to the scale, resolution, date and interpretation of the original source materials. You should consult available data documentation (metadata) for these particular data to determine their limitations and the precision to which they depict distance, direction, location or other geographic characteristics. These data may be subject to periodic change without prior notification. No Warranty: These data are provided as is, without any warranty whatsoever, including but not limited to any warranty as to their performance, merchantability, or fitness for any particular purpose. Liability: The entire risk as to the results of the use of these data is assumed by the user. LMIC is not responsible for any interpretation or conclusions based on these data made by those who acquire or use it. LMIC shall not be liable for any direct, indirect, special, incidental, compensatory or consequential damages or third party claims resulting from the use of these data, even if LMIC has been advised of the possibility of such potential loss or damage. In States that do not allow the exclusion or limitation of incidental or consequential damages, you may not use these data. Data Delivered on Electronic Media: If these data have been requested from LMIC on magnetic media, CD-ROM or any other physical media, LMIC will deliver this product in the computer-readable format agreed upon with the requestor. LMIC will re-issue these data if they are determined unreadable by correctly adjusted computer input devices, or when the medium is delivered in a damaged condition. Requests for re-issue of this digital data product must be made within 30 days of the date shipped from LMIC. |
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| Transfer Format Name | Arc/INFO Export | |||
| Transfer Format Version Number | 7.1.1 | |||
| Transfer Size | Varies by 100K tile | |||
| Ordering Instructions | Contact distributor | |||
| Online Linkage | none available | |||
| Section 7 | Metadata Reference Information | Top of full metadata | Top of page | |
| Metadata Date | 04/09/2007 | |||
| Contact Person Information | Susanne Maeder,
GIS Data Coordinator Minnesota Land Management Information Center (LMIC) 300 Centennial Building; 658 Cedar Street St. Paul, Minnesota 55155 Phone: 651.201.2488 FAX: 651.296.3698 E-mail: clearinghouse@state.mn.us |
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| Metadata Standard Name | Minnesota Geographic Metadata Guidelines | |||
| Metadata Standard Version | 1.1 | |||
| Metadata Standard Online Linkage | http://www.lmic.state.mn.us/gc/stds/metadata.htm | |||
This page last updated: 04/09/2007