To fill this data gap, CNHP has mapped fens for both the U.S. Forest Service (USFS) and the Colorado Department of Transportation (CDOT) through a series of contracts. To date, fen have been mapped on four National Forests, with work underway for six additional Forests, and along the entire CDOT right-of-way. For each project, potential fens are identified from digital aerial photography. Each potential fen polygon is hand-drawn in ArcGIS based on the best estimation of fen boundaries and attributed with a confidence value of 1 (low confidence), 3 (possible fen) or 5 (likely fen). CNHP photo interpreters rely on multiple image sources, as well as ancillary data such as topographic maps and wetland mapping form the National Wetlands Inventory.
Below are links to Fen Mapping Reports
- Fen Mapping for the Ashley National Forest
- Fen Mapping for the Manti-La Sal National Forest
- Fen Mapping for the Salmon-Challis National Forest
- Fen Mapping for the Rio Grande National Forest
- Wetland Mapping and Fen Survey in the White River National Forest 2011
- San Juan National Forest Botanical Survey of Fens