This feature class contains attribute information from four mid-level existing vegetation maps (1:100,000) prepared for the Chugach National Forest to provide up-to-date and more complete information about vegetative communities, structure, and patterns across the Forest. Approximately 3.7 million acres, 2.3 million acres of which are terrestrial and inland waterbodies and rivers, were mapped through a partnership between the Geospatial Technology and Applications Center (GTAC), Chugach National Forest, and the Alaska Regional Office. The Chugach National Forest and their partners prepared the regional classification system, identified the desired map units (map classes) and provided general project management. GTAC provided project support and expertise in vegetation mapping. A combination of field and photo interpreted reference data was used to inform the models that output the final map products. Federal personnel collected plot data on the ground, while Ducks Unlimited and GTAC personnel collected reference information from a helicopter.

Classification and regression models were used to characterize modeling units (mapping polygons) with the following vegetation attributes: 1) vegetation type; 2) tree canopy cover; 3) tree size; and 4) tall shrub canopy cover. The minimum map feature depicted on the map is 0.25 acres. All map products were designed according to the Forest Service mid-level vegetation mapping standards in order to be stored in the Forest GIS and National databases. This map product was generated using imagery primarily acquired in 2010 through 2020. The field data used as reference information for this mapping project was collected in the summer of 2021 and 2022. Therefore, the final map can be considered indicative of the existing vegetation conditions found within the project boundary in 2022.

For more detailed information on mapping methodology please see the Glacier Project Area Existing Vegetation Project Report.