Ecological Units—The National Hierarchical Framework of Ecological Units was formulated at a meeting of representatives from all Forest Service Regions, two Research Stations, the USDA Soil Conservation Service (now the Natural Resources Conservation Service), and the Nature Conservancy, and was adopted by the Forest Service in November, 1993.

Subsections are a refinement of this ecological unit hierarchy, based on physical and biological criteria. They allow integration of Forest- and Ranger District-level activities (e.g., timber harvest, monitoring, watershed analysis) into the broader scale analyses, assessments and management decision-making processes.

MAP OF SUBSECTIONS** (clickable, zoomable .pdf image)
NOTE: You will need Adobe Acrobat Reader (free download) to view .pdf files.
**TIP: If your browser freezes when you try to view this PDF file, you may need to download the latest verstion of Adobe Acrobat Reader. Older versions of Reader can cause some browsers to hang.

Ninety-one subsections are delineated on the 1996 map "Ecological Units of the Northern Region: Subsections."  Click on any subsection label to connect to a detailed description, exerpted from the reference document.


Nesser, J., G. Ford, C. Maynard, D. Page-Dumroese. 1997. Ecological Units of the Northern Region: Subsections. Gen. Tech. Rep. INT-GTR-369. [link to PDF added on 11/06/2011] Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 88 p.


Ecological units are described at the subsection level of the Forest Service National Hierarchical Framework of Ecological Units. This document consists of descriptions of the climate, geomorphology, geology, vegetation and soils that characterize each subsection. Included is information on sources of natural disturbances, current land use and ecological relationships of the major components.