The Border Field State Park Formerly Used Defense Site, or FUDS, is located in San Diego County, within the city of Imperial Beach, California. The Corps of Engineers is investigating and monitoring the former training area through the FUDS Program for munitions and explosive hazards that may remain from previous military activity. This page provides information on the Small Arms Range Complex, which is part of the Border Field State Park FUDS.
The Small Arms Range Complex was used for machine gun/small arms practice by the San Diego Naval Air Station from 1930 to 1946. The range complex consists of 249 land acres and 2,268 water acres. The FUDS-eligible portion of the Small Arms Range Complex extends 100 yards west of the California shoreline. The range complex contained a strafing range that was a multiple range complex used as both a strafing range and for machine gun training. The area also contained approximately five Jeep Moving Target Ranges and five mobile gun targets that were located along the dune area on the western portion of the Small Arms Range Complex. An additional mobile firing line was located near the center of the range. The targets were on rails, known as “Rabbit Tracks,” that would guide steam-driven targets for aircraft gunnery training. The Navy used .30- and .50-caliber ammunition for this training.
Prior to the Corps of Engineers beginning its investigation at the property in 1993, there had been reports of past responses by the Explosives Ordnance Disposal team to remove .50-caliber shells. In addition, there had also been reports of signal flares washing ashore from previous military training conducted by the Navy.
In 2003, a site visit was conducted in support of an Archives Search Report, but due to heavy rains and potentially hazardous site conditions, the team was not able to access the former range complex. A representative from the California Parks Department mentioned that approximately 3 to 4 feet of soil deposition overlay much of the site. The Tijuana River National Estuarine Reserve completed restoration projects and investigative research between 2005 and 2006. These activities included excavation of trench/test pits for the purpose of assessing cultural resources at the range. No munitions were found during these subsurface investigations; however, during the 2007 Site Inspection conducted by the Corps of Engineers, large amounts of small arms munitions debris were found at the Small Arms Range Complex.
The Small Arms Range Complex is located within the Tijuana River National Estuarine Research Reserve, Border Field State Park and Tijuana Slough National Wildlife Refuge. The Tijuana River National Estuarine is identified as a Wetlands of International Importance and is managed cooperatively by the U.S. Fish and Wildlife Service and the California Department of Parks and Recreation. The area preserves, protects and manages the natural and cultural resources of the Tijuana River Estuary. Border Field State Park is located within the Tijuana River National Estuarine Research Reserve, where visitors enjoy recreational activities such as hiking, horseback riding, bird watching and picnicking. The Tijuana Slough National Wildlife Refuge, also located in the reserve, is an important salt marsh that provides a critical habitat for federally listed endangered plants and animals.
The Corps of Engineers continues to investigate the Small Arms Range Complex to determine if additional clearance activities are required.