This dataset contains commonly used codes for counties and polygons representing boundaries for counties of the State of Iowa. Boundaries were developed from a set of 99 individual coverages of the Public Land Survey System (PLSS) for each county in the state. The PLSS coverages were digitized from paper copies of 7.5' topographic quadrangle maps. River boundaries were also digitized from 7.5' maps.

Downloadable H&T PDF City and County Maps.

This coverage contains polygons representing the county boundaries of the state of Iowa. COUNTY was developed from a set of 99 individual coverages of the Public Land Survey System (PLSS) for each county in the state. The PLSS coverages were digitized from paper copies of 7.5' topographic quadrangle maps. River boundaries were also digitized from 7.5' maps. This version also encompass' the Iowa-Nebraska Compact of 1943.

This coverage represents the current state boundary of Iowa. It was developed by digitizing, from 7.5' USGS Topgraphic maps, the sections of each county on a digitizing table, and thereafter dissolving them into county boundaries. Dissolving the counties into one state boundary was done, and later work added corrections from the Missouri River 1943 Compact Line..

The TIGER/Line shapefiles and related database files (.dbf) are an extract of selected geographic and cartographic information from the U.S. Census Bureau's Master Address File / Topologically Integrated Geographic Encoding and Referencing (MAF/TIGER) Database (MTDB). The MTDB represents a seamless national file with no overlaps or gaps between parts, however, each TIGER/Line shapefile is designed to stand alone as an independent data set, or they can be combined to cover the entire nation. The TIGER/Line shapefiles include both incorporated places (legal entities) and census designated places or CDPs (statistical entities). An incorporated place is established to provide governmental functions for a concentration of people as opposed to a minor civil division (MCD), which generally is created to provide services or administer an area without regard, necessarily, to population. Places always nest within a state, but may extend across county and county subdivision boundaries. An incorporated place usually is a city, town, village, or borough, but can have other legal descriptions. CDPs are delineated for the decennial census as the statistical counterparts of incorporated places. CDPs are delineated to provide data for settled concentrations of population that are identifiable by name, but are not legally incorporated under the laws of the state in which they are located. The boundaries for CDPs often are defined in partnership with state, local, and/or tribal officials and usually coincide with visible features or the boundary of an adjacent incorporated place or another legal entity. CDP boundaries often change from one decennial census to the next with changes in the settlement pattern and development; a CDP with the same name as in an earlier census does not necessarily have the same boundary. The only population/housing size requirement for CDPs is that they must contain some housing and population. The boundaries of most incorporated places in this shapefile are as of January 1, 2021, as reported through the Census Bureau's Boundary and Annexation Survey (BAS). The boundaries of all CDPs were delineated as part of the Census Bureau's Participant Statistical Areas Program (PSAP) for the 2020 Census.

The 2020 cartographic boundary KMLs are simplified representations of selected geographic areas from the U.S. Census Bureau's Master Address File / Topologically Integrated Geographic Encoding and Referencing (MAF/TIGER) Database (MTDB). These boundary files are specifically designed for small-scale thematic mapping. When possible, generalization is performed with the intent to maintain the hierarchical relationships among geographies and to maintain the alignment of geographies within a file set for a given year. Geographic areas may not align with the same areas from another year. Some geographies are available as nation-based files while others are available only as state-based files. County subdivisions are the primary divisions of counties and their equivalent entities for the reporting of Census Bureau data. They include legally-recognized minor civil divisions (MCDs) and statistical census county divisions (CCDs), and unorganized territories. In MCD states where no MCD exists or no MCD is defined, the Census Bureau creates statistical unorganized territories to complete coverage. The entire area of the United States, Puerto Rico, and the Island Areas are covered by county subdivisions. The generalized boundaries of legal MCDs are based on those as of January 1, 2020 as reported through the Census Bureau's Boundary and Annexation Survey (BAS). The generalized boundaries of all CCDs, delineated in 21 states, are those as reported as part of the Census Bureau's Participant Statistical Areas Program (PSAP) for the 2020 Census.

This coverage contains points that represent populated places, ie. cities, towns, villages or any other named place where people live. The coverage was developed from the USGS Geographic Names Information System (GNIS) database for Iowa. There were many errors in the original GNIS data, including missing points or mislocated points. The GNIS points were compared to two reference sources: USGS 100k scale county maps and Iowa DOT county highway maps. Mislocated and missing point were fixed and each town was designated as having been verified from one or the other reference sources or both. Some GNIS points were not verified from either source and are so designated (use these with caution).

Existing ROW layer was created by contacting county assessor's offices and based off of parcel data received from them. Each county has different levels of accuracy. If a county did not have a GIS parcel dataset, ERMS was utilized. strip maps were pulled from ERMS, georectified, and traced over to created the boundary. This dataset is not complete.

Scott County GPS Control: Scott County GPS Control Network monument locations. Originally collected in 2005 and subsequently reoccupied in 2015 and delivered in Iowa State Plane South, NAD83 (2011) and Iowa RCS Zone 11 coordinates. Davenport PLSS Corner Survey: Survey data acquired from Davenport regarding PLSS corners that they occupied over time using in-house survey equipment. Detailed information not available.PLSS Survey: Scott County PLSS corners occupied between 2007-2010 and originally referenced to Iowa State Plane, South NAD83 (HARN96) coordinate system. In 2015, a township level positional analysis and readjustment to NAD (2011) was conducted by third-party survey firms GB Consulting and DCI, Inc both incorporated in the State of Iowa.PLSS Index: Section corner reference database which represents locations of all known recorded corner certificates in Scott County as well as section corner documents kept by the Scott County Secondary Road Departments referred to as "Tie Books" (not recorded). Note that the physical location of corners in the PLSS Index database are approximate only. In contrast to the corners in layer PLSS Survey, the ones in PLSS Index are not survey grade and are for reference purposes only. However, the PLSS Index contains useful reference information such as when the corner was recorded, who recorded it, etc. and includes an online link to every section corner certificates and county tie book in the collection. There is a one-to-many relationship between features in the PLSS Index layer and the table, Certificate and Tie Book Records.

This coverage contains polygons representing the Iowa Boundary, it was derived from a coverage of county boundaries, called COUNTIES, of the state of Iowa. COUNTIES was developed from a set of 99 individual coverages of the Public Land Survey System (PLSS) for each county in the state. The PLSS coverages were digitized from paper copies of 7.5' topographic quadrangle maps. River boundaries were also digitized from 7.5' maps.

This resource is a member of a series. The TIGER/Line shapefiles and related database files (.dbf) are an extract of selected geographic and cartographic information from the U.S. Census Bureau's Master Address File / Topologically Integrated Geographic Encoding and Referencing (MAF/TIGER) System (MTS). The MTS represents a seamless national file with no overlaps or gaps between parts, however, each TIGER/Line shapefile is designed to stand alone as an independent data set, or they can be combined to cover the entire nation. Census tracts are small, relatively permanent statistical subdivisions of a county or equivalent entity and were defined by local participants as part of the 2020 Census Participant Statistical Areas Program. The Census Bureau delineated the census tracts in situations where no local participant existed or where all the potential participants declined to participate. The primary purpose of census tracts is to provide a stable set of geographic units for the presentation of census data and comparison back to previous decennial censuses. Census tracts generally have a population size between 1,200 and 8,000 people, with an optimum size of 4,000 people. When first delineated, census tracts were designed to be homogeneous with respect to population characteristics, economic status, and living conditions. The spatial size of census tracts varies widely depending on the density of settlement. Physical changes in street patterns caused by highway construction, new development, and so forth, may require boundary revisions. In addition, census tracts occasionally are split due to population growth, or combined because of substantial population decline. Census tract boundaries generally follow visible and identifiable features. They may follow legal boundaries such as minor civil division or incorporated place boundaries in some states and situations to allow for census tract-to-governmental unit relationships where the governmental boundaries tend to remain unchanged between censuses. State and county boundaries always are census tract boundaries in the standard Census Bureau geographic hierarchy. In a few rare instances, a census tract may consist of noncontiguous areas. These noncontiguous areas may occur where the census tracts are coextensive with all or parts of legal entities that are themselves noncontiguous.

The locally enhanced digital soil map (LE-DSM) dataset contains total of 48 maps of soil particle size fractions (psf) (sand, silt, and clay), texture classes, and organic matter (OM) content predicted by digital soil mapping methods and machine learning at 6 depth intervals of 0-5 cm, 5-15 cm, 15-30 cm, 30-60 cm, 60-100 cm, and 100-200 cm. The maps encompass 39 counties in north-central Iowa with a native resolution of 10 meters in the World Geodetic System 1984 Datum (WGS84) Universal Transverse Mercator (UTM) 15 North coordinate system. For soil particle size fractions (sand, silt, and clay), the original predictions were normalized to equal 100% and mapped. The normalized fractions were used to classify and map United States Department of Agriculture soil texture classes. The 48 maps are GeoTiffs, with the main file in TIF and other associated files such as XML, OVR, and TFW.Change Log: a prior version of this data set used the acronym "BUDSS" instead of "LE-DSM" and various typos have been corrected. Revised 2024-01

This GIS coverage represents an approximation of the public drainage district boundaries in Iowa. It also represents the infrastructure of the drainage districts, which includes tiles, and ditches. This information was digitized mainly from maps provided by county governments, usually the drainage clerk in that county. The accuracy of this coverage varies widely and should be used mainly as a guide, not exact ground conditions or locations.

This is a raster dataset of georeferenced township maps from the General Land Office (GLO) surveys beginning in 1836 through 1859. The source of the georeferenced images is scanned microfilm of plats from the State Archives. These plats represent maps drawn from the original field notes by the Surveyor General's Dubuque office.

The TIGER/Line shapefiles and related database files (.dbf) are an extract of selected geographic and cartographic information from the U.S. Census Bureau's Master Address File / Topologically Integrated Geographic Encoding and Referencing (MAF/TIGER) Database (MTDB). The MTDB represents a seamless national file with no overlaps or gaps between parts, however, each TIGER/Line shapefile is designed to stand alone as an independent data set, or they can be combined to cover the entire nation.Census Blocks are statistical areas bounded on all sides by visible features, such as streets, roads, streams, and railroad tracks, and/or by nonvisible boundaries such as city, town, township, and county limits, and short line-of-sight extensions of streets and roads. Census blocks are relatively small in area; for example, a block in a city bounded by streets. However, census blocks in remote areas are often large and irregular and may even be many square miles in area. A common misunderstanding is that data users think census blocks are used geographically to build all other census geographic areas, rather all other census geographic areas are updated and then used as the primary constraints, along with roads and water features, to delineate the tabulation blocks. As a result, all 2020 Census blocks nest within every other 2020 Census geographic area, so that Census Bureau statistical data can be tabulated at the block level and aggregated up to the appropriate geographic areas. Census blocks cover all territory in the United States, Puerto Rico, and the Island Areas (American Samoa, Guam, the Commonwealth of the Northern Mariana Islands, and the U.S. Virgin Islands). Blocks are the smallest geographic areas for which the Census Bureau publishes data from the decennial census. A block may consist of one or more faces.The TIGER/Line shapefiles and related database files (.dbf) are an extract of selected geographic and cartographic information from the U.S. Census Bureau's Master Address File / Topologically Integrated Geographic Encoding and Referencing (MAF/TIGER) Database (MTDB). The MTDB represents a seamless national file with no overlaps or gaps between parts, however, each TIGER/Line shapefile is designed to stand alone as an independent data set, or they can be combined to cover the entire nation.

The Digital Flood Insurance Rate Map (DFIRM) Database depicts flood risk information and supporting data used to develop the risk data. The primary risk classifications used are the 1-percent-annual-chance flood event, the 0.2-percent-annual- chance flood event, and areas of minimal flood risk. The DFIRM Database is derived from Flood Insurance Studies (FISs), previously published Flood Insurance Rate Maps (FIRMs), flood hazard analyses performed in support of the FISs and FIRMs, and new mapping data, where available. The FISs and FIRMs are published by the Federal Emergency Management Agency (FEMA). The file is georeferenced to earth's surface using the Ohio North Stateplane projection and coordinate system. The specifications for the horizontal control of DFIRM data files are consistent with those required for mapping at scales of 1:6000 and 1:12,000.

The Map of the Elevation of the Bedrock Surface 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 soils maps for Iowa. The soils 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. This allows the user a general feeling for the accuracy of the map; the more crenulated the contours, the more control was available for the mapping, and the more accurate is the mapping.

The 2015 cartographic boundary shapefiles are simplified representations of selected geographic areas from the U.S. Census Bureau's Master Address File / Topologically Integrated Geographic Encoding and Referencing (MAF/TIGER) Database (MTDB). These boundary files are specifically designed for small-scale thematic mapping. When possible, generalization is performed with the intent to maintain the hierarchical relationships among geographies and to maintain the alignment of geographies within a file set for a given year. Geographic areas may not align with the same areas from another year. Some geographies are available as nation-based files while others are available only as state-based files. The records in this file allow users to map the parts of Urban Areas that overlap a particular county. After each decennial census, the Census Bureau delineates urban areas that represent densely developed territory, encompassing residential, commercial, and other nonresidential urban land uses. In general, this territory consists of areas of high population density and urban land use resulting in a representation of the "urban footprint." There are two types of urban areas: urbanized areas (UAs) that contain 50,000 or more people and urban clusters (UCs) that contain at least 2,500 people, but fewer than 50,000 people (except in the U.S. Virgin Islands and Guam which each contain urban clusters with populations greater than 50,000). Each urban area is identified by a 5-character numeric census code that may contain leading zeroes. The primary legal divisions of most states are termed counties. In Louisiana, these divisions are known as parishes. In Alaska, which has no counties, the equivalent entities are the organized boroughs, city and boroughs, municipalities, and for the unorganized area, census areas. The latter are delineated cooperatively for statistical purposes by the State of Alaska and the Census Bureau. In four states (Maryland, Missouri, Nevada, and Virginia), there are one or more incorporated places that are independent of any county organization and thus constitute primary divisions of their states. These incorporated places are known as independent cities and are treated as equivalent entities for purposes of data presentation. The District of Columbia and Guam have no primary divisions, and each area is considered an equivalent entity for purposes of data presentation. The Census Bureau treats the following entities as equivalents of counties for purposes of data presentation: Municipios in Puerto Rico, Districts and Islands in American Samoa, Municipalities in the Commonwealth of the Northern Mariana Islands, and Islands in the U.S. Virgin Islands. The entire area of the United States, Puerto Rico, and the Island Areas is covered by counties or equivalent entities. The boundaries for counties and equivalent entities are as of January 1, 2010.

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.

This coverage contains polygons representing the PLSS township boundaries of the state of Iowa. TOWNSHIP was developed from a set of 99 individual county coverages of PLSS section lines. The county section coverages were appended together and section lines within a township were removed. The PLSS coverages were digitized from paper copies of 7.5' topo quad maps. River boundaries were also digitized from 7.5' maps.