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Description: Abstract: The CGS aims to provide geologic hazard susceptibility maps to state and local governments for use in their planning processes and mitigation plans. The Colorado Geological Survey (CGS) has begun developing landslide inventory and susceptibility maps for landslide-prone areas in Colorado. A lot of growth and development is taking place in the city of Boulder and the nearby towns in the county, near mesas and major drainages. Landslide deposits seem to be associated predominently with the hogbacks, incised drainages close the foothills, and glacial deposits in the subapline area of the county. The Landslide Susceptibility Map for Boulder County is part of a statewide effort to develop landslide inventory and susceptibility maps for landslide-prone areas in Colorado. A landslide is the failure and downslope movement of soil or rock due to the force of gravity exceeding the internal strength of the material. Methods: The landslide inventory was compiled by digitizing landslide deposits visible on 1-m resolution lidar datasets and high-resolution imagery, and joining it with previously cataloged landslide inventories from various published data sets and mapping projects. Please see accompanying text for more details.
Description: ABOUT THIS DATA:These polygons represent areas that may be susceptible to debris flows, especially during extreme precipitation events. New and existing structures, roadways, bridges, utilities, and other infrastructure located within these mapped debris-flow susceptible areas may be at risk of structural damage and/or sediment inundation. For new/proposed development within these areas, site-specific geologic hazard reports should be required prior to approval of land subdivision or the issuance of building permits. These reports should discuss the degree, limits, and potential impacts of the hazard to the proposed development or land use changes; proper debris-flow mitigation techniques; and feasibility of any recommended mitigation techniques.These polygons were compiled from various CGS Open-File Reports. Please refer to the original Open-File Report for additional information regarding mapping methodology and limitations of use.LIMITATIONS:These polygons depict generalized areas that may be susceptible to debris flows based on available GIS data and limited field observations in easily accessible areas. The polygons were generated at a scale of approximately 1:24,000 (1 inch = approx. 0.4 mi.) and are not valid if enlarged to scales greater than 1:24,000.The degree of susceptibility to a particular geologic hazard, in any given area, is related to ever-changing natural and human-induced conditions, and any alteration in the natural landscape may increase or decrease susceptibility to a particular hazard. The polygons are not intended to assign risk, or indicate the degree, severity, recurrence interval, or exact boundary of individual debris flows or debris-flow susceptible areas.Because of limitations associated with the mapping scale and the scope of this project, some areas that may be susceptible to potentially damaging but localized debris flows near the mouths of small gullies or at the base of steep slopes may not be included. Additionally, some higher-order streams in larger mountain valleys that have been mapped as debris flow susceptibility areas may be more likely to produce water floods than debris flows depending on local rainfall-runoff conditions and availability of erodible sediment and debris in the basin. Inclusion of existing structures and infrastructure within a mapped susceptibility area does not necessarily indicate that debris-flow impacts will occur, in only indicates that these features may be more exposed to debris-flow events than similar features located in other areas. This map should not be used in place of a detailed site-specific geologic hazard study.
Copyright Text: Polygons compiled by Kevin M. McCoy from various CGS Open-File Reports. Last updated December 14, 2018.
Description: The CGS completed a field inventory of abandoned and inactive hardrock mines on USFS lands in the State between 1991 and 1999. Approximately 18,000 abandoned mine-related features were inventoried. The USFS inventory process began with an office review of existing mining and geologic literature, previous mine inventories, and current/historical maps. Mine locations from these sources were compiled onto a work map. Aerial photographs (1:24,000-scale) were examined to locate potential mine sites not identified by other sources. Water quality information was used to identify streams potentially affected by acid mine drainage or other mine-site contaminants. When the office research process was complete, geologists visited specific mine locations (Sares et. al., 2000). Additional mines not identified in the literature search were found while performing the field inventory work.
Investigated mines were grouped geographically into “inventory areas” that were given identification numbers based on the Universal Transverse Mercator (UTM) coordinate system. An inventory area usually contained one to twenty mine features that could be grouped in relation to geographic features, such as a gulch or hillside. Mine features inventoried included adits, shafts, prospect pits, high walls, quarries, waste rock dumps, tailings, and spoils. All mine features within an inventory area were numbered sequentially (Sares et. al. 2000). Mine locations and data collected by the field geologists were entered on field forms and, subsequently, into a computer database and ArcGIS. Latitude/longitude information for each mine feature and water test were obtained by transferring mine location information from the field maps to Mylar overlays. Mine locations were then digitized from the overlays into ArcGIS (Sares et. al., 2000). Reportedly, some of the locations were also collected using a handheld GPS. Water quality data, such as pH and conductivity, were collected at all features where water was present, such as draining adits, seepage at the toe of dumps/tailings, and standing water in shafts. Water samples were collected where field tests indicated low pH and/or high conductivity, including several areas with natural acid rock drainage. Samples were analyzed for dissolved/total metals and for selected anions. The quality of any water associated with a mine feature was also assessed in the field by determining the pH, specific conductance, and physical observations. Observable characteristics were documented including precipitates and salts in the effluent drainage, opaque or cloudy water, stressed vegetation, and absence of aquatic organisms. This information was used to assign a qualitative “Environmental Degradation Rating” to the individual mine feature. Physical mine hazards were also rated in the field (Sares et. al., 2000). The CGS USFS database is in ArcGIS and Microsoft Access. Additional data, metadata, and database dictionary is included on CGS’s website (CGS, 2017). The data presented here are not intended to be used as a tool to assess risk. ANY DATA OR INFORMATION PROVIDED HERE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, WHETHER EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Data or information provided here shall be used and replied upon only at the user's sole risk, and the user agrees to indemnify and hold harmless the entities who provided the data and any other parties, its officials, officers and employees from any liability arising out of the user of the data/information provided. No warranty expressed or implied is made regarding the display or utility of the data, or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. The agencies who provided these data and the Colorado Geological Survey shall not be held liable for improper or incorrect use of the data described and/or contained herein.
Description: The CGS completed a field inventory of abandoned and inactive hardrock mines on USFS lands in the State between 1991 and 1999. Approximately 18,000 abandoned mine-related features were inventoried. The USFS inventory process began with an office review of existing mining and geologic literature, previous mine inventories, and current/historical maps. Mine locations from these sources were compiled onto a work map. Aerial photographs (1:24,000-scale) were examined to locate potential mine sites not identified by other sources. Water quality information was used to identify streams potentially affected by acid mine drainage or other mine-site contaminants. When the office research process was complete, geologists visited specific mine locations (Sares et. al., 2000). Additional mines not identified in the literature search were found while performing the field inventory work.
Investigated mines were grouped geographically into “inventory areas” that were given identification numbers based on the Universal Transverse Mercator (UTM) coordinate system. An inventory area usually contained one to twenty mine features that could be grouped in relation to geographic features, such as a gulch or hillside. Mine features inventoried included adits, shafts, prospect pits, high walls, quarries, waste rock dumps, tailings, and spoils. All mine features within an inventory area were numbered sequentially (Sares et. al. 2000). Mine locations and data collected by the field geologists were entered on field forms and, subsequently, into a computer database and ArcGIS. Latitude/longitude information for each mine feature and water test were obtained by transferring mine location information from the field maps to Mylar overlays. Mine locations were then digitized from the overlays into ArcGIS (Sares et. al., 2000). Reportedly, some of the locations were also collected using a handheld GPS. Water quality data, such as pH and conductivity, were collected at all features where water was present, such as draining adits, seepage at the toe of dumps/tailings, and standing water in shafts. Water samples were collected where field tests indicated low pH and/or high conductivity, including several areas with natural acid rock drainage. Samples were analyzed for dissolved/total metals and for selected anions. The quality of any water associated with a mine feature was also assessed in the field by determining the pH, specific conductance, and physical observations. Observable characteristics were documented including precipitates and salts in the effluent drainage, opaque or cloudy water, stressed vegetation, and absence of aquatic organisms. This information was used to assign a qualitative “Environmental Degradation Rating” to the individual mine feature. Physical mine hazards were also rated in the field (Sares et. al., 2000). The CGS USFS database is in ArcGIS and Microsoft Access. Additional data, metadata, and database dictionary is included on CGS’s website (CGS, 2017). The data presented here are not intended to be used as a tool to assess risk. ANY DATA OR INFORMATION PROVIDED HERE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, WHETHER EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Data or information provided here shall be used and replied upon only at the user's sole risk, and the user agrees to indemnify and hold harmless the entities who provided the data and any other parties, its officials, officers and employees from any liability arising out of the user of the data/information provided. No warranty expressed or implied is made regarding the display or utility of the data, or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. The agencies who provided these data and the Colorado Geological Survey shall not be held liable for improper or incorrect use of the data described and/or contained herein.
Description: The CGS completed a field inventory of abandoned and inactive hardrock mines on USFS lands in the State between 1991 and 1999. Approximately 18,000 abandoned mine-related features were inventoried. The USFS inventory process began with an office review of existing mining and geologic literature, previous mine inventories, and current/historical maps. Mine locations from these sources were compiled onto a work map. Aerial photographs (1:24,000-scale) were examined to locate potential mine sites not identified by other sources. Water quality information was used to identify streams potentially affected by acid mine drainage or other mine-site contaminants. When the office research process was complete, geologists visited specific mine locations (Sares et. al., 2000). Additional mines not identified in the literature search were found while performing the field inventory work.
Investigated mines were grouped geographically into “inventory areas” that were given identification numbers based on the Universal Transverse Mercator (UTM) coordinate system. An inventory area usually contained one to twenty mine features that could be grouped in relation to geographic features, such as a gulch or hillside. Mine features inventoried included adits, shafts, prospect pits, high walls, quarries, waste rock dumps, tailings, and spoils. All mine features within an inventory area were numbered sequentially (Sares et. al. 2000). Mine locations and data collected by the field geologists were entered on field forms and, subsequently, into a computer database and ArcGIS. Latitude/longitude information for each mine feature and water test were obtained by transferring mine location information from the field maps to Mylar overlays. Mine locations were then digitized from the overlays into ArcGIS (Sares et. al., 2000). Reportedly, some of the locations were also collected using a handheld GPS. Water quality data, such as pH and conductivity, were collected at all features where water was present, such as draining adits, seepage at the toe of dumps/tailings, and standing water in shafts. Water samples were collected where field tests indicated low pH and/or high conductivity, including several areas with natural acid rock drainage. Samples were analyzed for dissolved/total metals and for selected anions. The quality of any water associated with a mine feature was also assessed in the field by determining the pH, specific conductance, and physical observations. Observable characteristics were documented including precipitates and salts in the effluent drainage, opaque or cloudy water, stressed vegetation, and absence of aquatic organisms. This information was used to assign a qualitative “Environmental Degradation Rating” to the individual mine feature. Physical mine hazards were also rated in the field (Sares et. al., 2000). The CGS USFS database is in ArcGIS and Microsoft Access. Additional data, metadata, and database dictionary is included on CGS’s website (CGS, 2017). The data presented here are not intended to be used as a tool to assess risk. ANY DATA OR INFORMATION PROVIDED HERE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, WHETHER EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Data or information provided here shall be used and replied upon only at the user's sole risk, and the user agrees to indemnify and hold harmless the entities who provided the data and any other parties, its officials, officers and employees from any liability arising out of the user of the data/information provided. No warranty expressed or implied is made regarding the display or utility of the data, or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. The agencies who provided these data and the Colorado Geological Survey shall not be held liable for improper or incorrect use of the data described and/or contained herein.
Description: The CGS completed a field inventory of abandoned and inactive hardrock mines on USFS lands in the State between 1991 and 1999. Approximately 18,000 abandoned mine-related features were inventoried. The USFS inventory process began with an office review of existing mining and geologic literature, previous mine inventories, and current/historical maps. Mine locations from these sources were compiled onto a work map. Aerial photographs (1:24,000-scale) were examined to locate potential mine sites not identified by other sources. Water quality information was used to identify streams potentially affected by acid mine drainage or other mine-site contaminants. When the office research process was complete, geologists visited specific mine locations (Sares et. al., 2000). Additional mines not identified in the literature search were found while performing the field inventory work.
Investigated mines were grouped geographically into “inventory areas” that were given identification numbers based on the Universal Transverse Mercator (UTM) coordinate system. An inventory area usually contained one to twenty mine features that could be grouped in relation to geographic features, such as a gulch or hillside. Mine features inventoried included adits, shafts, prospect pits, high walls, quarries, waste rock dumps, tailings, and spoils. All mine features within an inventory area were numbered sequentially (Sares et. al. 2000). Mine locations and data collected by the field geologists were entered on field forms and, subsequently, into a computer database and ArcGIS. Latitude/longitude information for each mine feature and water test were obtained by transferring mine location information from the field maps to Mylar overlays. Mine locations were then digitized from the overlays into ArcGIS (Sares et. al., 2000). Reportedly, some of the locations were also collected using a handheld GPS. Water quality data, such as pH and conductivity, were collected at all features where water was present, such as draining adits, seepage at the toe of dumps/tailings, and standing water in shafts. Water samples were collected where field tests indicated low pH and/or high conductivity, including several areas with natural acid rock drainage. Samples were analyzed for dissolved/total metals and for selected anions. The quality of any water associated with a mine feature was also assessed in the field by determining the pH, specific conductance, and physical observations. Observable characteristics were documented including precipitates and salts in the effluent drainage, opaque or cloudy water, stressed vegetation, and absence of aquatic organisms. This information was used to assign a qualitative “Environmental Degradation Rating” to the individual mine feature. Physical mine hazards were also rated in the field (Sares et. al., 2000). The CGS USFS database is in ArcGIS and Microsoft Access. Additional data, metadata, and database dictionary is included on CGS’s website (CGS, 2017). The data presented here are not intended to be used as a tool to assess risk. ANY DATA OR INFORMATION PROVIDED HERE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, WHETHER EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Data or information provided here shall be used and replied upon only at the user's sole risk, and the user agrees to indemnify and hold harmless the entities who provided the data and any other parties, its officials, officers and employees from any liability arising out of the user of the data/information provided. No warranty expressed or implied is made regarding the display or utility of the data, or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. The agencies who provided these data and the Colorado Geological Survey shall not be held liable for improper or incorrect use of the data described and/or contained herein.
Description: The CGS completed a field inventory of abandoned and inactive hardrock mines on USFS lands in the State between 1991 and 1999. Approximately 18,000 abandoned mine-related features were inventoried. The USFS inventory process began with an office review of existing mining and geologic literature, previous mine inventories, and current/historical maps. Mine locations from these sources were compiled onto a work map. Aerial photographs (1:24,000-scale) were examined to locate potential mine sites not identified by other sources. Water quality information was used to identify streams potentially affected by acid mine drainage or other mine-site contaminants. When the office research process was complete, geologists visited specific mine locations (Sares et. al., 2000). Additional mines not identified in the literature search were found while performing the field inventory work.
Investigated mines were grouped geographically into “inventory areas” that were given identification numbers based on the Universal Transverse Mercator (UTM) coordinate system. An inventory area usually contained one to twenty mine features that could be grouped in relation to geographic features, such as a gulch or hillside. Mine features inventoried included adits, shafts, prospect pits, high walls, quarries, waste rock dumps, tailings, and spoils. All mine features within an inventory area were numbered sequentially (Sares et. al. 2000). Mine locations and data collected by the field geologists were entered on field forms and, subsequently, into a computer database and ArcGIS. Latitude/longitude information for each mine feature and water test were obtained by transferring mine location information from the field maps to Mylar overlays. Mine locations were then digitized from the overlays into ArcGIS (Sares et. al., 2000). Reportedly, some of the locations were also collected using a handheld GPS. Water quality data, such as pH and conductivity, were collected at all features where water was present, such as draining adits, seepage at the toe of dumps/tailings, and standing water in shafts. Water samples were collected where field tests indicated low pH and/or high conductivity, including several areas with natural acid rock drainage. Samples were analyzed for dissolved/total metals and for selected anions. The quality of any water associated with a mine feature was also assessed in the field by determining the pH, specific conductance, and physical observations. Observable characteristics were documented including precipitates and salts in the effluent drainage, opaque or cloudy water, stressed vegetation, and absence of aquatic organisms. This information was used to assign a qualitative “Environmental Degradation Rating” to the individual mine feature. Physical mine hazards were also rated in the field (Sares et. al., 2000). The CGS USFS database is in ArcGIS and Microsoft Access. Additional data, metadata, and database dictionary is included on CGS’s website (CGS, 2017). The data presented here are not intended to be used as a tool to assess risk. ANY DATA OR INFORMATION PROVIDED HERE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, WHETHER EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Data or information provided here shall be used and replied upon only at the user's sole risk, and the user agrees to indemnify and hold harmless the entities who provided the data and any other parties, its officials, officers and employees from any liability arising out of the user of the data/information provided. No warranty expressed or implied is made regarding the display or utility of the data, or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. The agencies who provided these data and the Colorado Geological Survey shall not be held liable for improper or incorrect use of the data described and/or contained herein.
Description: The CGS completed a field inventory of abandoned and inactive hardrock mines on USFS lands in the State between 1991 and 1999. Approximately 18,000 abandoned mine-related features were inventoried. The USFS inventory process began with an office review of existing mining and geologic literature, previous mine inventories, and current/historical maps. Mine locations from these sources were compiled onto a work map. Aerial photographs (1:24,000-scale) were examined to locate potential mine sites not identified by other sources. Water quality information was used to identify streams potentially affected by acid mine drainage or other mine-site contaminants. When the office research process was complete, geologists visited specific mine locations (Sares et. al., 2000). Additional mines not identified in the literature search were found while performing the field inventory work.
Investigated mines were grouped geographically into “inventory areas” that were given identification numbers based on the Universal Transverse Mercator (UTM) coordinate system. An inventory area usually contained one to twenty mine features that could be grouped in relation to geographic features, such as a gulch or hillside. Mine features inventoried included adits, shafts, prospect pits, high walls, quarries, waste rock dumps, tailings, and spoils. All mine features within an inventory area were numbered sequentially (Sares et. al. 2000). Mine locations and data collected by the field geologists were entered on field forms and, subsequently, into a computer database and ArcGIS. Latitude/longitude information for each mine feature and water test were obtained by transferring mine location information from the field maps to Mylar overlays. Mine locations were then digitized from the overlays into ArcGIS (Sares et. al., 2000). Reportedly, some of the locations were also collected using a handheld GPS. Water quality data, such as pH and conductivity, were collected at all features where water was present, such as draining adits, seepage at the toe of dumps/tailings, and standing water in shafts. Water samples were collected where field tests indicated low pH and/or high conductivity, including several areas with natural acid rock drainage. Samples were analyzed for dissolved/total metals and for selected anions. The quality of any water associated with a mine feature was also assessed in the field by determining the pH, specific conductance, and physical observations. Observable characteristics were documented including precipitates and salts in the effluent drainage, opaque or cloudy water, stressed vegetation, and absence of aquatic organisms. This information was used to assign a qualitative “Environmental Degradation Rating” to the individual mine feature. Physical mine hazards were also rated in the field (Sares et. al., 2000). The CGS USFS database is in ArcGIS and Microsoft Access. Additional data, metadata, and database dictionary is included on CGS’s website (CGS, 2017). The data presented here are not intended to be used as a tool to assess risk. ANY DATA OR INFORMATION PROVIDED HERE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, WHETHER EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Data or information provided here shall be used and replied upon only at the user's sole risk, and the user agrees to indemnify and hold harmless the entities who provided the data and any other parties, its officials, officers and employees from any liability arising out of the user of the data/information provided. No warranty expressed or implied is made regarding the display or utility of the data, or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. The agencies who provided these data and the Colorado Geological Survey shall not be held liable for improper or incorrect use of the data described and/or contained herein.
Unique Value Renderer: Field 1: Mine_Categ Field 2: N/A Field 3: N/A Field Delimiter: , Default Symbol:
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Default Label: N/A UniqueValueInfos:
Value: Red - Draining mines without recent investigations or restoration project. Label: Red - Draining mines without recent investigations or restoration project. Description: N/A Symbol:
Value: Yellow - Draining mines with recent investigation or restoration project in process. Label: Yellow - Draining mines with recent investigation or restoration project in process. Description: N/A Symbol:
Value: Green - Draining mines with partial to complete restoration. Label: Green - Draining mines with partial to complete restoration. Description: N/A Symbol: