Aspen completed vegetation mapping along the lower seven miles (430 acres) of the San Luis Rey River. Aerial photography, GPS and walking transects were used to map plant communities. A GIS analysis determined the acreage of good and poor quality riparian habitat for least Bell's vireo based on cover and composition attributes recorded during the survey.

San Luis Rey River Biological Assessment. Aspen completed a biological assessment for the U.S. Army Corps of Engineers of eight federally listed threatened and endangered birds, amphibians, and fish. The impact of proposed vegetation clearing and sediment removal on the species and their habitat was assessed based on hydrological modeling results, vegetation surveys, and wildlife population data; over 20 detailed mitigation measures were defined.