This dataset contains 50-ft contours for the Hot Springs shallowest unit of the Ouachita Mountains aquifer system potentiometric-surface map. The potentiometric-surface shows altitude at which the water level would have risen in tightly-cased wells and represents synoptic conditions during the summer of 2017. Contours were constructed from 59 water-level measurements measured in selected wells (locations in the well point dataset). Major streams and creeks were selected in the study area from the USGS National Hydrography Dataset (U.S. Geological Survey, 2017), and the spring point dataset with 18 spring altitudes calculated from 10-meter digital elevation model (DEM) data (U.S. Geological Survey, 2015; U.S. Geological Survey, 2016). After collecting, processing, and plotting the data, a potentiometric surface was generated using the interpolation method Topo to Raster in ArcMap 10.5 (Esri, 2017a). This tool is specifically designed for the creation of digital elevation models and imposes constraints that ensure a connected drainage structure and a correct representation of the surface from the provided contour data (Esri, 2017a). Once the raster surface was created, 50-ft contour interval were generated using Contour (Spatial Analyst), a spatial analyst tool (available through ArcGIS 3D Analyst toolbox) that creates a line-feature class of contours (isolines) from the raster surface (Esri, 2017b). The Topo to Raster and contouring done by ArcMap 10.5 is a rapid way to interpolate data, but computer programs do not account for hydrologic connections between groundwater and surface water. For this reason, some contours were manually adjusted based on topographical influence, a comparison with the potentiometric surface of Kresse and Hays (2009), and data-point water-level altitudes to more accurately represent the potentiometric surface. Select References: Esri, 2017a, How Topo to Raster works—Help | ArcGIS Desktop, accessed December 5, 2017, at ArcGIS Pro at http://pro.arcgis.com/en/pro-app/tool-reference/3d-analyst/how-topo-to-raster-works.htm. Esri, 2017b, Contour—Help | ArcGIS Desktop, accessed December 5, 2017, at ArcGIS Pro Raster Surface toolset at http://pro.arcgis.com/en/pro-app/tool-reference/3d-analyst/contour.htm. Kresse, T.M., and Hays, P.D., 2009, Geochemistry, Comparative Analysis, and Physical and Chemical Characteristics of the Thermal Waters East of Hot Springs National Park, Arkansas, 2006-09: U.S. Geological Survey 2009–5263, 48 p., accessed November 28, 2017, at https://pubs.usgs.gov/sir/2009/5263/. U.S. Geological Survey, 2015, USGS NED 1 arc-second n35w094 1 x 1 degree ArcGrid 2015, accessed December 5, 2017, at The National Map: Elevation at https://nationalmap.gov/elevation.html. U.S. Geological Survey, 2016, USGS NED 1 arc-second n35w093 1 x 1 degree ArcGrid 2016, accessed December 5, 2017, at The National Map: Elevation at https://nationalmap.gov/elevation.html.

Use the app to find the downloadable area within Jackson County - 2 Foot Contour MapThe 2-foot Contour Map shows contours that were derived from several different LiDAR projects in the Rogue Valley over the last 10 years. The map can be used to both download and view the contour data. To use the map, search or zoom in to an address. When zoomed in to a specific scale, the map will change from the downloadable areas layer to 2-foot interval contour lines. The LiDAR Project Dates layer can be used to identify the date when the elevation was collected in an area. Please note that data is available only for the valley floor areas at this time.The 2ft contours were created from 1-meter pixel DEM and then cleaned to remove very small elevation changes and to create a smooth contour line. This information should not be used to create topographic surveys or other applications where the precise elevation of a location is required. For additional information on LiDAR in Oregon or to download the source data, please visit the DOGAMI Lidar Viewer.The downloadable data is a zipped ESRI Shapefile and is projected to Oregon State Plane South (Intl Feet) with NAD 1983 datum.

This web service depicts raster contour lines that are generated on-the-fly from 3-ft. NC Dept. of Public Safety DEMs using the ArcGIS contour function. They are created for visualization and have been smoothed for a more cartographic-pleasing appearance. These contour lines do not have elevation values attached to them. However, if displayed in a GIS application, an "identify" on the map will display the elevation value of the contour based on the 3-ft. DEM source. This contour layer can be overlaid on a map and provide information regarding terrain without obscuring the underlying data. The contour interval is 100 ft.The DEMs these raster contours are based on can be downloaded from the Direct Data Downloads section on the NCOneMap.gov website. Unsmoothed vector contour lines can also be downloaded. Do not use the map to download the raster contours (JPG, PNG, etc).

Statistical analyses and maps representing mean, high, and low water-level conditions in the surface water and groundwater of Miami-Dade County were made by the U.S. Geological Survey, in cooperation with the Miami-Dade County Department of Regulatory and Economic Resources, to help inform decisions necessary for urban planning and development. Sixteen maps were created that show contours of (1) the mean of daily water levels at each site during October and May for the 2000-2009 water years; (2) the 25th, 50th, and 75th percentiles of the daily water levels at each site during October and May and for all months during 2000-2009; and (3) the differences between mean October and May water levels, as well as the differences in the percentiles of water levels for all months, between 1990-1999 and 2000-2009. The 80th, 90th, and 96th percentiles of the annual maximums of daily groundwater levels during 1974-2009 (a 35-year period) were computed to provide an indication of unusually high groundwater-level conditions. These maps and statistics provide a generalized understanding of the variations of water levels in the aquifer, rather than a survey of concurrent water levels. Water-level measurements from 473 sites in Miami-Dade County and surrounding counties were analyzed to generate statistical analyses. The monitored water levels included surface-water levels in canals and wetland areas and groundwater levels in the Biscayne aquifer. Maps were created by importing site coordinates, summary water-level statistics, and completeness of record statistics into a geographic information system, and by interpolating between water levels at monitoring sites in the canals and water levels along the coastline. Raster surfaces were created from these data by using the triangular irregular network interpolation method. The raster surfaces were contoured by using geographic information system software. These contours were imprecise in some areas because the software could not fully evaluate the hydrology given available information; therefore, contours were manually modified where necessary. The ability to evaluate differences in water levels between 1990-1999 and 2000-2009 is limited in some areas because most of the monitoring sites did not have 80 percent complete records for one or both of these periods. The quality of the analyses was limited by (1) deficiencies in spatial coverage; (2) the combination of pre- and post-construction water levels in areas where canals, levees, retention basins, detention basins, or water-control structures were installed or removed; (3) an inability to address the potential effects of the vertical hydraulic head gradient on water levels in wells of different depths; and (4) an inability to correct for the differences between daily water-level statistics. Contours are dashed in areas where the locations of contours have been approximated because of the uncertainty caused by these limitations. Although the ability of the maps to depict differences in water levels between 1990-1999 and 2000-2009 was limited by missing data, results indicate that near the coast water levels were generally higher in May during 2000-2009 than during 1990-1999; and that inland water levels were generally lower during 2000-2009 than during 1990-1999. Generally, the 25th, 50th, and 75th percentiles of water levels from all months were also higher near the coast and lower inland during 2000–2009 than during 1990-1999. Mean October water levels during 2000-2009 were generally higher than during 1990-1999 in much of western Miami-Dade County, but were lower in a large part of eastern Miami-Dade County.

This web service depicts raster contour lines that are generated on-the-fly from 3-ft. NC Dept. of Public Safety DEMs using the ArcGIS contour function. They are created for visualization and have been smoothed for a more cartographic-pleasing appearance. These contour lines do not have elevation values attached to them. However, if displayed in a GIS application, an "identify" on the map will display the elevation value of the contour based on the 3-ft. DEM source. This contour layer can be overlaid on a map and provide information regarding terrain without obscuring the underlying data. The contour interval is 4 ft.The DEMs these raster contours are based on can be downloaded from the Direct Data Downloads section on the NCOneMap.gov website. Unsmoothed vector contour lines can also be downloaded. Do not use the map to download the raster contours (JPG, PNG, etc).

City of Seattle 2 ft contours derived from Lidar captured in 2021. Contour lines display at 2ft, 10ft and 50ft intervals dependent on scale. Lines have been smoothed and generalized for display and performance.

Development Detail:

This vector tile service includes topographic contour lines representing elevation at 2-foot intervals within the city of Seattle.

The contours were derived from a bare earth - digital elevation model (DEM) with a pixel resolution of 1.5 feet. The lidar data that created the DEM were collected by NV5 Geospatial over the spring and summer months of 2021 and provided to the city by King County in 2022.

The DEM used to generate the contours was filtered using the Focal Statistics tool in ArcGIS, which served to limit some abrupt changes in cell values. A 3x3 rectangular neighborhood analysis was applied and a mean value was calculated per raster cell.

After running the Focal Statistics tool, 2-foot contours were generated from the filtered DEM. To reduce file size and improve performance, the contours were generalized further using the Smooth Line tool in ArcGIS. A smoothing algorithm type of Polynomial Approximation with Exponential Kernel (PAEK) and a smoothing tolerance of 20 feet was selected in the Smooth Line tool parameter options.

Finally, after executing both generalization tools (Focal Statistics and Smooth Line), all lines less than 25 feet in length were omitted from the final output.

Please note: The 2-foot contours are intended to be used for general reference and cartographic purposes only and should not be used for analysis purposes.

This dataset was created to represent the land surface elevation at 1:24,000 scale for Florida. The elevation contour lines representing the land surface elevation were digitized from United States Geological survey 1:24,000 (7.5 minute) quadrangles and were compiled by South Florida, South West Florida, St. Johns River and Suwannee River Water Management Districts and FDEP. QA and corrections to the data were supplied by the Florida Department of Environmental Protection's Florida Geological Survey and the Division of Water Resource Management. This data, representing over 1,000 USGS topographic maps, spans a variety of contour intervals including 1 and 2 meter and 5 and 10 foot. The elevation values have been normalized to feet in the final data layer. Attributes for closed topographic depressions were also captured where closed (hautchered) features were identified and the lowest elevation determined using the closest contour line minus one-half the contour interval. This data was derived from the USGS 1:24,000 topographic map series. The data is more than 20 years old and is likely out-of-date in areas of high human activity.

10-foot elevation contours for the extent of the state of Indiana, created from downloading, projecting and combining several datasets from USGS based on 7.5-minute quadrangle boundaries. These vector contour lines are derived from the 3D Elevation Program using automated and semi-automated processes. They were created to support 1:24,000-scale CONUS and Hawaii, 1:25,000-scale Alaska, and 1:20,000-scale Puerto Rico / US Virgin Island topographic map products, but are also published in this GIS vector format. Contour intervals are assigned by 7.5-minute quadrangle, so this vector dataset is not visually seamless across quadrangle boundaries. The vector lines have elevation attributes (in feet above mean sea level on NAVD88), but this dataset does not carry line symbols or annotation. Description from the original source metadata: These vector contour lines are derived from the 3D Elevation Program using automated and semi-automated processes. They were created to support 1:24,000-scale CONUS and Hawaii, 1:25,000-scale Alaska, and 1:20,000-scale Puerto Rico / US Virgin Island topographic map products, but are also published in this GIS vector format. Contour intervals are assigned by 7.5-minute quadrangle, so this vector dataset is not visually seamless across quadrangle boundaries. The vector lines have elevation attributes (in feet above mean sea level on NAVD88), but this dataset does not carry line symbols or annotation.Source files downloaded from The National Map on 11/18/2019:https://prd-tnm.s3.amazonaws.com/StagedProducts/Contours/GDB/ELEV_Muncie_W_IN_1X1_GDB.ziphttps://prd-tnm.s3.amazonaws.com/StagedProducts/Contours/GDB/ELEV_Danville_E_IN_1X1_GDB.ziphttps://prd-tnm.s3.amazonaws.com/StagedProducts/Contours/GDB/ELEV_Vincennes_E_IN_1X1_GDB.ziphttps://prd-tnm.s3.amazonaws.com/StagedProducts/Contours/GDB/ELEV_Louisville_W_KY_1X1_GDB.ziphttps://prd-tnm.s3.amazonaws.com/StagedProducts/Contours/GDB/ELEV_Cincinnati_W_IN_1X1_GDB.ziphttps://prd-tnm.s3.amazonaws.com/StagedProducts/Contours/GDB/ELEV_Indianapolis_E_IN_1X1_GDB.ziphttps://prd-tnm.s3.amazonaws.com/StagedProducts/Contours/GDB/ELEV_Fort_Wayne_W_IN_1X1_GDB.ziphttps://prd-tnm.s3.amazonaws.com/StagedProducts/Contours/GDB/ELEV_Chicago_E_IN_1X1_GDB.ziphttps://prd-tnm.s3.amazonaws.com/StagedProducts/Contours/GDB/ELEV_Indianapolis_W_IN_1X1_GDB.ziphttps://prd-tnm.s3.amazonaws.com/StagedProducts/Contours/GDB/ELEV_Danville_W_IL_1X1_GDB.ziphttps://prd-tnm.s3.amazonaws.com/StagedProducts/Contours/GDB/ELEV_Vincennes_W_IN_1X1_GDB.ziphttps://prd-tnm.s3.amazonaws.com/StagedProducts/Contours/GDB/ELEV_Chicago_W_IL_1X1_GDB.ziphttps://prd-tnm.s3.amazonaws.com/StagedProducts/Contours/GDB/ELEV_Cincinnati_E_OH_1X1_GDB.ziphttps://prd-tnm.s3.amazonaws.com/StagedProducts/Contours/GDB/ELEV_Muncie_E_IN_1X1_GDB.ziphttps://prd-tnm.s3.amazonaws.com/StagedProducts/Contours/GDB/ELEV_Louisville_E_KY_1X1_GDB.zip https://prd-tnm.s3.amazonaws.com/StagedProducts/Contours/GDB/ELEV_Fort_Wayne_E_IN_1X1_GDB.ziphttps://prd-tnm.s3.amazonaws.com/StagedProducts/Contours/GDB/ELEV_Evansville_E_IN_1X1_GDB.ziphttps://prd-tnm.s3.amazonaws.com/StagedProducts/Contours/GDB/ELEV_Evansville_W_IN_1X1_GDB.zip

Use the app to find the downloadable area within Jackson County - 2 Foot Contour MapThe 2-foot Contour Map shows contours that were derived from several different LiDAR projects in the Rogue Valley over the last 10 years. The map can be used to both download and view the contour data. To use the map, search or zoom in to an address. When zoomed in to a specific scale, the map will change from the downloadable areas layer to 2-foot interval contour lines. The LiDAR Project Dates layer can be used to identify the date when the elevation was collected in an area. Please note that data is available only for the valley floor areas at this time.The 2ft contours were created from 1-meter pixel DEM and then cleaned to remove very small elevation changes and to create a smooth contour line. This information should not be used to create topographic surveys or other applications where the precise elevation of a location is required. For additional information on LiDAR in Oregon or to download the source data, please visit the DOGAMI Lidar Viewer.The downloadable data is a zipped ESRI Shapefile and is projected to Oregon State Plane South (Intl Feet) with NAD 1983 datum.

20 foot contours (2008). This dataset contains locations and attributes of 20-ft interval topography data, created as part of the DC Geographic Information System (DC GIS) for the D.C. Office of the Chief Technology Officer (OCTO) and participating D.C. government agencies. In addition to the 2-ft contour data ancillary datasets containing an ESRI geodatabase of masspoints and breaklines.

Upper Applegate 2ft Contours Use the app to find the downloadable area within Jackson County - 2 Foot Contour MapThe 2-foot Contour Map shows contours that were derived from several different LiDAR projects in the Rogue Valley over the last 10 years. The map can be used to both download and view the contour data. To use the map, search or zoom in to an address. When zoomed in to a specific scale, the map will change from the downloadable areas layer to 2-foot interval contour lines. The LiDAR Project Dates layer can be used to identify the date when the elevation was collected in an area. Please note that data is available only for the valley floor areas at this time.The 2ft contours were created from 1-meter pixel DEM and then cleaned to remove very small elevation changes and to create a smooth contour line. This information should not be used to create topographic surveys or other applications where the precise elevation of a location is required. For additional information on LiDAR in Oregon or to download the source data, please visit the DOGAMI Lidar Viewer.The downloadable data is a zipped ESRI Shapefile and is projected to Oregon State Plane South (Intl Feet) with NAD 1983 datum.

Source:1 foot contours were generated for each production block from the final bare earth DEMs using ArcGIS software. Using ArcGIS software, the contours were validated for correct topology, including must not intersect, must not self intersect, and must not have dangles. Contours are then manually reviewed with the 3D breaklines to ensure complete coverage, correct coding, data integrity and that contours behave correctly around water bodies, water crossings, and elevated features such as overpasses. The contours are then clipped to individual tiles as creating one dataset for the entire project renders the feature class un-usable. Enclosed contours completely within building footprints were removed from the final contour dataset. Coordinate System:The data was developed based on a horizontal datum/projection of NAD83 (2011), State Plane Connecticut, U.S. Survey Feet and vertical datum of NAVD88 (GEOID18) Development:This vector tile package contains contour lines originally derived in the State Plane coordinate system. Prior to generating the tile service, individual contour blocks were merged into a single, seamless data layer to ensure consistency and completeness across the project area. This unified dataset served as the basis for creating the vector tile package. During the creation of the vector tile index, Web Mercator was used as the tiling reference to enable proper indexing and tile generation within ArcGIS Online. Please note that while the vector tile index references Web Mercator for mapping and display purposes, the contour line geometries are aligned with the original State Plane coordinate system, maintaining consistency with the source data used in production. This vector tile package contains contour lines originally derived in the State Plane coordinate system. Prior to generating the tile service, individual contour blocks were merged into a single, seamless data layer to ensure consistency and completeness across the project area. This unified dataset served as the basis for creating the vector tile package. During the creation of the vector tile index, Web Mercator was used as the tiling reference to enable proper indexing and tile generation within ArcGIS Online. Please note that while the vector tile index references Web Mercator for mapping and display purposes, but the contour lines were originally in the State Plane coordinate system Use Constraints:There are no formal use restrictions. However, users should be aware the conditions may have changed since the data was originally collected, and some areas may no longer accurately reflect current surface features. This data should not be used for critical decision-making without a full understanding of their limitations.

Statistical analyses and maps representing mean, high, and low water-level conditions in the surface water and groundwater of Miami-Dade County were made by the U.S. Geological Survey, in cooperation with the Miami-Dade County Department of Regulatory and Economic Resources, to help inform decisions necessary for urban planning and development. Sixteen maps were created that show contours of (1) the mean of daily water levels at each site during October and May for the 2000-2009 water years; (2) the 25th, 50th, and 75th percentiles of the daily water levels at each site during October and May and for all months during 2000-2009; and (3) the differences between mean October and May water levels, as well as the differences in the percentiles of water levels for all months, between 1990-1999 and 2000-2009. The 80th, 90th, and 96th percentiles of the annual maximums of daily groundwater levels during 1974-2009 (a 35-year period) were computed to provide an indication of unusually hig ...

The terrain dataset and contours were created using aerial Lidar collected on March 25, 2022 at a density of greater than 12 points per square meter. Lidar points classified as ground were used as the basis of the terrain model. Breaklines were added around bridges, retaining walls, and other sharp features to improve the accuracy around sudden breaks in the terrain. Breaklines were also added along significant bodies of water to assist with hydro-enforcement. The final terrain dataset was used to generate 1-foot contours. RMSEz = 0.33 feet.

Statistical analyses and maps representing mean, high, and low water-level conditions in the surface water and groundwater of Miami-Dade County were made by the U.S. Geological Survey, in cooperation with the Miami-Dade County Department of Regulatory and Economic Resources, to help inform decisions necessary for urban planning and development. Sixteen maps were created that show contours of (1) the mean of daily water levels at each site during October and May for the 2000-2009 water years; (2) the 25th, 50th, and 75th percentiles of the daily water levels at each site during October and May and for all months during 2000-2009; and (3) the differences between mean October and May water levels, as well as the differences in the percentiles of water levels for all months, between 1990-1999 and 2000-2009. The 80th, 90th, and 96th percentiles of the annual maximums of daily groundwater levels during 1974-2009 (a 35-year period) were computed to provide an indication of unusually high groundwater-level conditions. These maps and statistics provide a generalized understanding of the variations of water levels in the aquifer, rather than a survey of concurrent water levels. Water-level measurements from 473 sites in Miami-Dade County and surrounding counties were analyzed to generate statistical analyses. The monitored water levels included surface-water levels in canals and wetland areas and groundwater levels in the Biscayne aquifer. Maps were created by importing site coordinates, summary water-level statistics, and completeness of record statistics into a geographic information system, and by interpolating between water levels at monitoring sites in the canals and water levels along the coastline. Raster surfaces were created from these data by using the triangular irregular network interpolation method. The raster surfaces were contoured by using geographic information system software. These contours were imprecise in some areas because the software could not fully evaluate the hydrology given available information; therefore, contours were manually modified where necessary. The ability to evaluate differences in water levels between 1990-1999 and 2000-2009 is limited in some areas because most of the monitoring sites did not have 80 percent complete records for one or both of these periods. The quality of the analyses was limited by (1) deficiencies in spatial coverage; (2) the combination of pre- and post-construction water levels in areas where canals, levees, retention basins, detention basins, or water-control structures were installed or removed; (3) an inability to address the potential effects of the vertical hydraulic head gradient on water levels in wells of different depths; and (4) an inability to correct for the differences between daily water-level statistics. Contours are dashed in areas where the locations of contours have been approximated because of the uncertainty caused by these limitations. Although the ability of the maps to depict differences in water levels between 1990-1999 and 2000-2009 was limited by missing data, results indicate that near the coast water levels were generally higher in May during 2000-2009 than during 1990-1999; and that inland water levels were generally lower during 2000-2009 than during 1990-1999. Generally, the 25th, 50th, and 75th percentiles of water levels from all months were also higher near the coast and lower inland during 2000–2009 than during 1990-1999. Mean October water levels during 2000-2009 were generally higher than during 1990-1999 in much of western Miami-Dade County, but were lower in a large part of eastern Miami-Dade County.

Contours are lines of equal elevation. This is a contour feature layer for the state of Connecticut derived from the index contour in the 1' contour data set. All closed polygons less than 35' length have been deleted to improve loading performance. This data set is derived from the 2023 Lidar with15 to 20 points per meter squared.Source:1 foot contours were generated for each production block from the final bare earth DEMs using ArcGIS software. Contours are labeled as intermediate or index with index contours set to every 10th interval. Using ArcGIS software, the contours were validated for correct topology, including must not intersect, must not self intersect, and must not have dangles. Contours are then manually reviewed with the 3D breaklines to ensure complete coverage, correct coding, data integrity and that contours behave correctly around water bodies, water crossings, and elevated features such as overpasses. The contours are then clipped to individual tiles as creating one dataset for the entire project renders the feature class un-usable. Enclosed contours completely within building footprints were removed from the final contour dataset.Coordinate System:The data was developed based on a horizontal datum/projection of NAD83 (2011), State Plane Connecticut, U.S. Survey Feet and vertical datum of NAVD88 (GEOID18)Contours were cut by Town then merged into COGsGeographic ExtentCoverage: State of Connecticut ClassificationsSensitivity: PublicUsage: Public UseQuality: High QualityKnown Quality Issues: None known, but subject to standard limitations of third-party commercial data CurrencyCreated: 2023Update Frequency: Per FlightLast Updated: August 2023

0.6 meter contours. This dataset contains locations and attributes of 0.6 meter interval topography data, created using bare earth points from the lidar point cloud data. Some areas have limited data. The lidar dataset redaction was conducted under the guidance of the United States Secret Service. All data returns were removed from the dataset within the United States Secret Service redaction boundary except for classified ground points and classified water points.

The goal of the Atlantic Subsurface Stratigraphic Initiative (ASSI) is to create isopach and structural contour maps for all Coastal Plain formations within the Salisbury Embayment of Maryland and Virginia. Detailed information regarding thicknesses and extent of formations across state boundaries can then be utilized for more accurate documentation of the subaerial extent of aquifers across states. In support of this goal, lower Paleogene sediment elevation and thickness information from approximately 600+ data points from wells, cores, outcrops, and geologic maps were obtained from published and unpublished resources. Analyses started with production of a structure contour map of the unconformable contact of the Danian Brightseat Formation with underlying Cretaceous sediments, which represents the Cretaceous-Paleogene boundary in the Embayment. In addition, an isopach map of the Brightseat was produced using the Natural Neighbors interpolator in ArcGIS, creating a raster grid file that was symbolized every five feet. Results indicate a central depocenter with a thickness of 95 feet within Maryland with smaller thicknesses of the Brightseat surrounding. Although Danian sediments in southeastern Virginia were removed by the Chesapeake Bay impact event, up to 30 ft of possible Brightseat Formation has been identified from core and well data in southernmost Virginia.

Kentucky's LiDAR-derived, cartographic quality, 10ft contours generated using ArcGIS. A smoothing function was applied during creation so as to create contours appropriate for use in a wide variety of cartographic applications. This dataset is best utilized between 1:1,000 and 1:36,000 but was created specifically for use at 1:24,000.