Township, Range and Section
The PLSS data provides a labeled grid showing the section boundaries in OpenSpace format and can be imported into any version of XMap 5 or newer (see the “Importing into XMap” tab). Each file contains coverage for a single state, with the exception of California, which is divided into northern and southern regions, and Alaska, which is divided into northern, western, eastern, southwestern, and southeastern regions.
The Public Land Survey System is a method of surveying and describing the land and has traditionally been used to determine parcel ownership. The system is applied to most of the U.S. States, particularly those that lie west of the Mississippi River.
Using a rectangular grid system derived from a base line that runs east-west and a Principal Meridian that runs north-south within each survey area, the PLSS creates a series of 6-square-mile Townships. These are identified by a Township (TWP) number and direction indicator (N or S) relative to the base line and range number and direction indicator (E or W) relative to the Principal Meridian.
Townships are normally divided into 36 1-square-mile Sections that are assigned a sequential number value.
The resulting Township, Range, and Section designation is commonly referred using the following method:
T140S R630W S27
In this case, the area in question is Township 140 south of the survey’s Base Line, Range 630 west of the Principal Meridian and Section 27. See the sample to the right.
How to Download
Use the following steps to download a PLSS layer:
- Right-click on the name of the state or region you want to download.
- Select Save Target As... or Save Link As… from the shortcut menu.
- Browse to the location where you want to save the compressed file to your hard drive and then click Save. Each downloaded file will have a .zip suffix.
- Unzip the file using an extraction program and save the .openspace and text files it contains to your hard drive.
Each downloaded state includes a text file that provides instructions on importing the data into XMap, searching for a particular Township, Range, and Section, and turning the layer on and off.
Importing into XMap
To Import PLSS Files into XMap:
- Select the GIS tab and click the Workspace subtab button to the left of the tab area
- Click the Layers button above the Workspace table and click Import to open the Import Layer wizard.
- Browse to the location where the PLSS file (.openspace) was unzipped, select the file, and click Open*.
- Select a database from the Database drop-down list in the Import Layer window and click the Next button. The layer import begins.
*To bypass the first three steps of the import process, drag the OpenSpace Transfer file into the map window in XMap.
The PLSS layer includes the following attributes for each section polygon:
- TWP – Township number
- TWP_DIR – Township direction, usually N (north) or S (south) of the survey baseline
- RNG – Range number
- RNG_DIR – Range direction, usually E (east) or W (west) of the principal meridian
- SEC – Section number
To Search for a Particular Township, Range, and Section:
- Select the Attributes subtab button to the left of the tab area.
- Click the Query drop-down list, and choose Search by TWP RNG & SEC.
- Click the Run button to open the Run Query dialog box.
- Enter the necessary information and click Run. The results of the query are highlighted on the map and in the attributes table.
To cancel the query and revert the selected section polygon to its default color, choose Cancel Query from the same drop-down list.
Managing the PLSS Layer
To turn the PLSS layer on or off, select or clear the check box next to the layer name in the Workspace table or on the Map Data tab.
Referencing Section Polygons
Section polygons are labeled using the following format:
T12N R13E S17
In this example T12N refers to Township 12 North; R13E refers to Range 13 East; and S17 refers to Section 17. Because of the text decluttering process within XMap, labels may not appear at lower zoom levels.
About Using the Polygons with XMap Professional, Editor and Enterprise
Users of XMap Professional cannot change the color of the polygons, the style of the label, or any of the other characteristics of the layer; however, users of either the GIS Editor or Enterprise versions of XMap can modify the layer in numerous ways. For instance, the polygon color can be changed, the labels can be removed or edited, additional queries can be built, and selected areas within the layer can be highlighted and used to create a new layer. For details on how to perform any of these functions, refer to the Help system in XMap.