This site provides free access to Iowa geographic map data, including aerial photography, orthophotos, elevation maps, and historical maps. The data is available through an on-line map viewer and through Web Map Service (WMS) connections for GIS. The site was developed by the Iowa State University Geographic Information Systems Support and Research Facility in cooperation with the Iowa Department of Natural Resources, the USDA Natural Resources Conservation Service, and the Massachusetts Institute of Technology. This site was first launched in March 1999.

This Digital Elevation Model (DEM) of the bedrock surface elevation in Iowa was compiled using all available data, principally information from GEOSAM, supplemented with well and boring information from the Iowa DOT, exposure reports from Iowa Geological & Water Survey reports and files, and the Department of Soil Conservation county soil maps for Iowa. The soil maps were especially valuable, since they identified soils that encountered bedrock within the soil horizon, and less dependably also spot-located rock exposures. A 50 foot contour interval was chosen for the map because it was considered to best represent the accuracy of the well data, allowed for fairly good representation of the bedrock surface in areas with limited well control, and was mappable in high relief areas (the contours packed so close together that it precluded mapping or forced the software to snap-join contours). The 50 foot contour interval also allowed areas where bedrock was present within the soil horizon (2-3 feet) to be treated as areas of exposures. In these areas the bedrock elevation was mapped as only slightly below the surface elevation, so contours on the 7«' topographic maps were closely followed in mapping the bedrock elevation. Consequently, on the completed map of bedrock elevation, these areas display much more contorted and crenulated contour lines than the areas where only drill control was utilized.

The National Elevation Dataset (NED) is a primary elevation data product that has been produced and distributed by the U.S. Geological Survey (USGS). Since its inception, the USGS has compiled and published topographic information in many forms, and the NED is a significant development in this long line of products that describe the land surface. The NED provides seamless raster elevation data of the conterminous United States (CONUS), Alaska, Hawaii, U.S. island territories, Mexico, and Canada. The NED is derived from diverse source datasets that are processed to a specification with consistent resolutions, coordinate system, elevation units, and horizontal and vertical datums. The NED was developed as the logical result of the maturation of the long-standing USGS elevation program, which for many years concentrated on production of quadrangle-based digital elevation models (DEM). The NED contributes to the elevation layer of The National Map, and it provides basic elevation information for earth science studies and mapping applications in the U.S. and most of North America.For over 15 years (1999–2014), the NED served as the flagship elevation product of the USGS. In 2015, the 3D Elevation Program (3DEP) was initiated. When the 3DEP initiative became operational, the name “National Elevation Dataset” (and the abbreviation “NED”) were retired as the USGS elevation activities and data were rebranded under the 3DEP banner. However, elevation data produced and distributed as part of the NED are still widely used (and distributed by other entities), so there is a continuing need for detailed documentation, including how it was produced, its accuracy, and how it is used.

U.S. Geological Survey (USGS) scientists conducted field data collection efforts between October 25th and 31st, 2020 at several sites in eastern Iowa using high accuracy surveying technologies. The work was initiated as an effort to validate commercially acquired topographic light detection and ranging (lidar) data that was collected between December 7th, 2019 and November 19th, 2020 using wide area mapping lidar systems for the USGS 3D Elevation Program (3DEP). The goal was to compare and validate the airborne lidar data to topographic, structural, and infrastructural data collected through more traditional means (e.g., Global Navigational Satellite System (GNSS) surveying). Evaluating these data will provide valuable information on the performance of wide area topographic lidar mapping capabilities that are becoming more widely used in 3DEP. The airborne lidar was collected to support the U.S. Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) High Resolution Elevation Enterprise Program and the Iowa Department of Agriculture and Land Stewardship Iowa Flood Plain Program, in addition to the 3DEP mission. The data contained within this particular release are comprised of conventional survey (i.e. total station and GNSS) and ground based lidar data.

2 Foot Contours of Iowa, Derived from LiDAR Data. Full Metadata: ftp://ftp.igsb.uiowa.edu/gis_library/ia_state/elevation/contours_2ft/contours_2ft.html

This data set represents a digital elevation model (DEM) of the land surface of Iowa, in the UTM projection, Zone 15, NAD83 horizontal datum, with elevation in centimeters NAVD 88 vertical datum. The DEM has a horizontal resolution of 3 meters and was aggregated from one meter resolution elevation data from the state of Iowa's LiDAR program. The aggregation process uses a 3x3 pixel moving average window, which helps to smooth out noise in the one meter data, but also softens sharp edges of landscape features such as ditches and ridges, which may be undesirable for some purposes. The DEM was then Integerizied to shrink the size of the file, so final units are in centimeters. Water features sometimes have a triangular appearance due to lack of lidar returns over water and should be ignored.

Digital raster graphic (1:100,000-scale DRG) is a scanned image of a US Geological Survey (USGS) standard series topographic map. The image is georeferenced to the surface of the earth and fit to the Universal Transverse Mercator projection.

The Horizontal surface is a plane 150’ above the established airport elevation. The perimeter of which is constructed by swinging arcs of specified radii from the center of each end of the primary surface and connecting adjacent arcs by lines tangent to those arcs.

This is collection level metadata for LAS and ASCII data files from the statewide Iowa Lidar Project. The Iowa Light Detection and Ranging (LiDAR) Project collects location and elevation (X, Y, Z) data to a set standard for the entire state of Iowa. LIDAR is defined as an airborne laser system, flown aboard rotary or fixed-wing aircraft, that is used to acquire x, y, and z coordinates of terrain and terrain features that are both manmade and naturally occurring. LIDAR systems consist of a light-emitting scanning laser, an airborne Global Positioning System (GPS) with attendant GPS base station(s), and an Inertial Measuring Unit (IMU). The laser scanning system measures ranges from the scanning laser to terrain surfaces by measuring the time it takes for the emitted light (LIDAR return) to reach the earth's surface and reflect back to the onboard LIDAR detector. The airborne GPS system ascertains the in-flight three-dimensional position of the sensor, and the IMU delivers precise information about the attitude of the sensor. The LIDAR system incorporates data from these three subsystems to produce a large cloud of points on the land surface whose X, Y, and Z coordinates are known within the specified accuracy. This collection consists of ASCII files of bare earth elevations and intensity (x,y,z,i) and, LAS (version 1.0 lidar data interchange standard) binary files that include all 1st and last returns, intensity and bare earth classification.

This is a metadata compilation for geologic bedrock maps of Iowa. Maps listed: Estimated Depth to Bedrock, Iowa Bedrock Geology, Iowa Bedrock Surface Elevation (raster), Iowa Bedrock Surface Elevation (vector). The compilation is published as an Excel workbook containing header features including title, description, author, citation, originator, distributor, and resource URL links to scanned maps for download. The Excel workbook contains seven worksheets, including information about the template, notes related to revisions of the template, resource provider information, the data, a field list (data mapping view) and vocabularies (data valid terms) used to populate the data worksheet . This resource was provided by the Iowa Geological and Water Survey and made available for distribution through the National Geothermal Data System.

An interactive map of contour maps, fishing structure locations, topography and more.

Color hillshade maps from 2007-2010 high resolution LiDAR terrain mapping project. The Iowa DNR, USDA Natural Resources Conservation Service and other partners funded a multi-year project to collect high-resolution LiDAR terrain data for the State of Iowa. These hillshade maps are a derivative product from 1-meter resolution digital elevation models (DEM) from the LiDAR bare-earth datasets

This coverage outlines the boundary of the Loess Hills in Iowa at 1:100,000 scale. Criteria applied to the delineation of the Loess Hills included drainage density, drainage divides, density of isolated hillforms, crenulated contours, slopes greater than 15%, presence of catstep features, general loess thickness and earlier mapping. The following sources were utilized: 1:100,000 and 1:24,000 scale USGS topographic maps, USDA-NRCS STATSGO Soil Survey Grid Information, Digital Elevation Module, and the 1:2,000,000 Landforms of Iowa Coverage.

Elevation of bedrock surface in Iowa. for more information or to download the file, see links provided.

This feature layer contains Linn County, Iowa 2 foot contours derived from a statewide LiDAR projected conducted in 2019-2020.For more information about this project, please contact the State of Iowa.The Elevation field within this feature layer represents the elevation above sea level in feet.Update FrequencyNeverAdditional ResourcesVisit Linn County, Iowa on the web.Visit Linn County, Iowa GIS on the web. This site is updated as needed to reflect maps, apps, and data of interest from various County departments.Contact InformationQuestions? Contact the GIS Division by phone at 319.892.5250 or by email.

Geospatial (GIS) Data on glacial topography derived from LiDAR elevation data. Contains GIS vector data (in ESRI file geodatabases) that characterize the geometry ofglacial landforms created during the last glaciation (12,000 to 14,000 years ago), such as moraines, ice walled lake plains, doubly breached doughnuts and eskers and is supplementedby online LiDAR derived elevation data. For easy data access, an ArcGIS Pro 3.0 project (aprx) file is provided.

Surface elevation of Galena Group (Ordovician-age) aquifer.

Terrain data, as defined in FEMA Guidelines and Specifications, Appendix N: Data Capture Standards, describes the digital topographic data that was used to create the elevation data representing the terrain environment of a watershed and/or floodplain. Terrain data requirements allow for flexibility in the types of information provided as sources used to produce final terrain deliverables. Once this type of data is provided, FEMA will be able to account for the origins of the flood study elevation data. (Source: FEMA Guidelines and Specifications, Appendix N, Section N.1.2). NAD83 State Plane Missouri Central Zone FIPS 2402 is the projection and coordinate system for this project.

Terrain data, as defined in FEMA Guidelines and Specifications, Appendix M: Data Capture Standards, describes the digital topographic data that was used to create the elevation data representing the terrain environment of a watershed and/or floodplain. Terrain data requirements allow for flexibility in the types of information provided as sources used to produce final terrain deliverables. Once this type of data is provided, FEMA will be able to account for the origins of the flood study elevation data. (Source: FEMA Guidelines and Specifications, Appendix M, Section M.4).

Surface elevation of Silurian-age strata. Iowa Hydrogeologic Map Server - Silurian Surface Elevation