A depiction of the boundary that encompasses a Ranger District and its sub units. A Sub Unit is where the district is not one continuesarea or polygon. For example the sky islands of the Coronado in Sothern Arizona. This dataset is derived from the USFS Southwestern Region ALP (Automated Lands Program) data Project. This is one of fourteen layers derived from ALP for the purpose of supplying data layers for recourse GIS analysis and data needs within the Forest Service. The fourteen layers are Administrative Forest, Administrative Region, National Grassland, Ranger District, Military Reserve, Other National Designated Area, Proclaimed Forest, Section, Special Interest Management Area, Surface Ownership, Surface Ownership Dissolve, Township, Wilderness Status, and Wild Scenic River . There were some gapes in the ALP data so a small portion of this dataset comes from CCF (Cartographic Feature Files) datasets and the USFS Southwestern Region Core Data Project. ALP data is developed from data sources of differing accuracy, scales, and reliability. Where available it is developed from GCDB (Geographic Coordinate Data Base) data. GCDB data is maintained by the Bureau of Land Management in their State Offices. GCDB data is mostly corner data. Not all corners and not all boundaries are available in GCDB so ALP also utilizes many other data sources like CFF data to derive its boundaries. GCDB data is in a constant state of change because land corners are always getting resurveyed. The GCDB data used in this dataset represents a snapshot in time at the time the GCDB dataset was published by the BLM and may not reflect the most current GCDB dataset available. The Forest Service makes no expressed or implied warranty with respect to the character, function, or capabilities of these data. These data are intended to be used for planning and analyses purposes only and are not legally binding with regards to title or location of National Forest System lands.