||trs displays the smallest unit in the Public Land Survey System; Township/Ranges are subdivided into 36 Sections; each Section is approximately one square mile. The coverage format includes a tr (Township) region subclass.
This layer has been adjusted to Section corner data from the GIS parcel Section AutoCAD drawings. It also includes the half Township South of 12S14E Sections 31-34, designated as 12F14E (field TR).
Known Errors/Qualifications: The Canoa Land Grant area is not part of the Public Land Survey System. The trs layer includes sections in the Canoa Land Grant area as if it had been included in the survey.
9/2013: While this layer is maintained as a Shapefile, the coverage format is still required for certain nightly processing. See Steve Whitney.
Lineage: The TRS layer for Pima County was extracted from a state-wide layer of PLSS Section boundaries as received from ALRIS. The ALRIS layer was tablet digitized from USGS 7.5 minute topographic quadrangle paper maps.
In 1992, a database of Section corner locations was acquired from ADOT, and the TRS layer was adjusted to match those ADOT Section corners that were surveyed to an acceptable level.
In 2010, the Section boundaries were adjusted to Section corner locations from the GIS parcel AutoCAD drawings.
Spatial Domain: Pima County
Maintenance Format: Shape
Primary Source Organization: ALRIS
Primary Source Date: 1988
Primary Source Scale: 24000
Primary Source Format: Coverage
Secondary Source Organization: Pima County DOT
Secondary Source Contact: Steve Whitney
Secondary Source Date: 1992
Secondary Source Format: Database
GIS Contact: Steve Whitney
MapGuide Layer Name: Section Grid
MapGuide Scale Range: 0 - 100000