HELIX Environmental Planning (HELIX) managed an Environmental Assessment (EA) and a Biological Assessment (BA) that addressed a proposed new multi-purpose training area on approximately 633 acres of former agricultural fields at Marine Corps Base (MCB) Camp Pendleton in northern San Diego County. The training range, now in operation, accommodates (1) heavy equipment/assault breacher vehicle training; (2) a company-sized Forward Operating Base; (3) Military Operations on Urban Terrain training; and (4) convoy operations/Counter Improvised Explosive Device training. Work was performed for Naval Facilities Engineering Command Southwest. In addition to the EA and BA, HELIX’s deliverables included a jurisdictional delineation report, report on invasive Johnson grass, cultural resources field studies and evaluations, and California Coastal Commission Negative Determination.