HELIX Environmental Planning (HELIX) prepared a Biological Assessment (BA) and Environmental Assessment (EA) for a proposed action that would increase personnel end strength, and the bed-down of temporary and permanent supporting facilities at the Marine Corps Air Station (MCAS) Miramar in the City of San Diego. The proposed action was a localized component of the broader U.S. Marine Corps (USMC) 202K Plus Up Initiative (also known as Grow the Force). Under the Grow the Force initiative, the total USMC end strength would increase from approximately 180,000 Marines to 202,000 by 2011. This would be accomplished through incremental annual increases in the existing war-fighting organization of the USMC, and by the reallocation of existing facilities and the construction of new support facilities at several USMC installations. The proposed action evaluated in the EA involved the increase of up to 600 Marines at MCAS Miramar over the course of four years through the construction of five permanent facilities including the repair/upgrade of existing facilities and the construction of associated site improvements and infrastructure needed to support the permanent facilities. The biological assessment focused on three federally listed species (San Diego fairy shrimp, San Diego button-celery, and coastal California gnatcatcher).