SUPPORT LAYERS TAB

The Search Tab contains a variety of addition maps which may be placed above the base map. These layers may be used for reference and additional context. They are grouped into four categories:

(1) Parcels: the boundaries of all county parcels.

(2) Political Boundaries: the boundaries of all county parcels.

• Cities: This data set consists of county city limits.
• Supervisor Districts: An interactive web map application displaying supervisor district boundaries within Navajo County, supporting governance, public engagement, and decision-making.
• School Districts: This dataset provides a general reference for schools and learning sites in Arizona, containing essential fields for school name and type classification.
• Voting Precincts: This dataset defines the vote precinct boundaries within Navajo County, providing a geographic reference for electoral administration, voter assignments, and precinct-based voting districts.
• PLSS Township, Range, Section : This dataset contains the BLM Public Land Survey System (PLSS) Township and First Division Section boundaries that intersect the Navajo County corporate limits, providing a geographic reference for land management, legal descriptions, and cadastral mapping. The PLSS dataset defines the official Township and First Division Section boundaries established by the Bureau of Land Management (BLM) within Navajo County, Arizona. These survey divisions play a crucial role in land records, property delineation, and resource management, supporting legal descriptions, land transactions, and jurisdictional oversight. Used by government agencies, land surveyors, GIS professionals, and property developers, this dataset facilitates cadastral mapping, boundary verification, and land-use planning, ensuring accurate land division references for regulatory and administrative purposes.
• Congressional Boundaries: This data set consists of US Congressional Districts for Arizona for 2020.
• township, Range, Section: This dataset consists of the Township, Range and Section grid lines.
• Ownership Type: The LAND data set was first started in 1984 and updated in the spring 1988 by the State Land Department Forestry Division and ALRIS. The PLSS data originated from the Department of Transportation (ADOT). The data was then projected into ARC/INFO format and edited using the procedures from the ASLD 'Land Status Map Digitizing Procedure' guide. The data set covers the entire State of Arizona, is regularly updated and managed cooperatively by the ASLD GIS section and the Arizona BLM GIS Department. The data are created to serve as base information for use in GIS systems for a variety of planning and analysis purposes. These data do not represent a legal record.

(3) Census Boundaries: the boundaries of all county parcels.

• Census Blocks: This data set consists of the polygonal boundaries for the Census 2020 Blocks for Arizona. Census Blocks are statistical areas bounded on all sides by visible features such as streets, roads, streams and railroad tracks, and by invisible boundaries such as city, town, township, and county limits and short imaginary extensions of streets and roads. Generally census blocks are small in area, for example a block in a city bounded by streets. However, census blocks in remote areas may be large and irregular and contain hundreds of square miles. Census blocks never cross county or census tract boundaries.
• Census Groups: This data set consists of the polygonal boundaries for the 2020 Census Block Groups for Arizona. A census block group (BG) is a cluster of census blocks having the same first digit of their four-digit identifying numbers within a census tract. For example, Block Group 3 (BG 3) within a census tract includes all blocks numbered from 3000 to 3999. Block groups generally contain between 600 and 3,000 people, with an optimum population size of 1,500. Block groups never cross the boundaries of States, Counties or census tracts.
• Census Tracts: This data set consists of the polygonal boundaries for the 2020 Census Tracts for Arizona. Census tracts are small, relatively permanent statistical subdivisions of a county delineated by local participants as part of the U.S. Census Bureau's Participant Statistical Areas Program. The U.S. Census Bureau delineated census tracts in situations where no local participant existed or where local or tribal governments declined to participate. The primary purpose of census tracts is to provide a stable set of geographic units for the presentation of decennial census data. Census tracts generally have between 1,500 and 8,000 people, with an optimum size of 4,000 people. (Counties with fewer people have a single census tract.) When first delineated, census tracts are 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. Census tract boundaries are delineated with the intention of being maintained over many decades so that statistical comparisons can be made from decennial census to decennial census. However, physical changes in street patterns caused by highway construction, new developments, and so forth, may require occasional boundary revisions. In addition, census tracts occasionally are split due to population growth or combined as a result of substantial population decline. Census tracts are identified by a four-digit basic number and may have a two-digit numeric suffix; for example, 6059.02. The decimal point separating the four-digit basic tract number from the two-digit suffix is shown in the printed reports and on census maps. In computer-readable files, the decimal point is implied.

(4) Hydrologic Features: the boundaries of all county parcels.

• Flood Hazard Zones: the generalize boundaries of flood hazard area.
• Lakes: This dataset consists of various hydro polygon features found within Arizona.
• Springs: This data set consists of spring locations in Arizona and incorporates information extracted from both the USGS Geonames database and the USGS Digital Line Graphs (DLG's).
• Streams: Converted in the fall of 1988 from USGS 1:100,000 scale DLG data to ARC format. Since then, multiple and extensive corrections have taken place. Early on, several Arizona agencies were part of rectification including: attributes, features, edge matching and the re-tiling of the data into the USGS Hydrologic Unit Code (HUC) library tiling format. The Environmental Protection Agency (EPA) has since added critical attributes to the Arizona database, including: A nationally recognized management link code (the Reach Id), names, and hydrologic information. Arizona has enhanced the theme further by adding ergonomic Descriptive Attribute Codes, Cartographic Order, more Names, and intense Quality Assurance Controls
• Watershed Boundaries: This data set consists of Hydrologic unit code areas (drainage basins) in Arizona. This data set, whose sole purpose was to be used as the Hydro Library's Index Coverage (Map Library Tiles), was digitized from both 1:24,000 scale and 1:250,000 scale USDI Geological Survey (USGS) quadrangle maps. When using source maps at a scale of 1:250,000, a special effort was made to digitize the boundaries in conformance with the STREAMS hydrography data layer (e.g., the tile boundaries never crossed stream features except at appropriate stream confluences).

(5) Geology: the boundaries of all county parcels.

• 50 Contours: This dataset represents selected contour intervals for the State of Arizona. Datasets are available for 50',100, 250', and 500' intervals. Each file covers an Arizona county or part of a county and as a collection covers the entire state. The data were created by processing hill shade TIF files derived from the U.S. Geological Survey National Elevation Dataset. The processing produced ESRI formatted coverages for each county or part of a county. The U.S. Geological Survey has developed a National Elevation Dataset (NED). The NED is a seamless mosaic of best-available elevation data. The 7.5-minute elevation data for the conterminous United States are the primary initial source data. In addition to the availability of complete 7.5-minute data, efficient processing methods were developed to filter production artifacts in the existing data, convert to the NAD83 datum, edge-match, and fill slivers of missing data at quadrangle seams. One of the effects of the NED processing steps is a much-improved base of elevation data for calculating slope and hydrologic derivatives. The specifications for the NED 1 arc second and 1/3 arc second data are - Geographic coordinate system, Horizontal datum of NAD83, except for AK which is NAD27, Vertical datum of NAVD88, except for AK which is NAVD29, Z units of meters.
• Geology Type: This data set consists of geologic formations in Arizona. The data are created to serve as base information for use in GIS systems for a variety of planning and analysis purposes. These data do not represent a legal record.
• Faults: This data set consists of geologic fault formations in Arizona.
• Mines: This data set is derived from the Bureau of Mines Minerals Availability System (MAS) data set. Most of the information is from the Minerals Industry System Location (MILS) table. The data are created to serve as base information for use in GIS systems for a variety of planning and analysis purposes. These data do not represent a legal record.
• Game and Fish Vegetation: This data set consists of Arizona's natural vegetation. The data are created to serve as base information for use in GIS systems for a variety of planning and analysis purposes. These data do not represent a legal record. The manuscripts were drawn during 1976 by the various wildlife managers (game wardens) of the Arizona Game and Fish Department. The scale of the manuscript maps was one half inch to one mile (1:126,720) and the base maps were the 'County General' series provided by the Arizona Department of Transportation. The map attributes represent Arizona's natural vegetation as delineated in the 'Journal of the Arizona Academy of Science', Volume 9, supplement 2, Appendix F, published May 1974 using a classification scheme developed by David E. Brown and Charles H. Lowe. The University of Arizona did the digitizing of the gfveg manuscript during 1992 and 1993. Note: This is a different classification than the one appearing on Brown and Lowe's, 'Natural Vegetation of the Southwest' which is the cover NAVEG.
• Native Vegetation: Digital representation of Brown and Lowe's "Biotic Communities of the Southwest" map (1979) developed by The Nature Conservancy in Arizona (2004). This map is intended for broad, regional, landscape-scale analysis. The source scale of these data is 1:1,000,000.

The following controls are used to manage the support layers: