Salton Sea Test Base: The Desert Lake’s Atomic-Era History

The Salton Sea’s military history reaches beyond the concrete foundations of Camp Dunlap. On the lake’s southwestern shore, another installation brought together seaplanes, test aircraft, cameras, and the engineering teams behind America’s emerging nuclear arsenal.

The Salton Sea Test Base was part of atomic-weapons development, but its defining postwar work involved inert test units. Engineers studied how designs behaved in flight and under environmental conditions. That distinction is the key to understanding the site: a nuclear weapon’s delivery and reliability could be tested without producing a nuclear explosion.

A different base on a different shore

The former Salton Sea Test Base occupied a southwestern shoreline site in Imperial County. The Navy traces its establishment to a naval air facility in 1942. Readers arriving from our Camp Dunlap history should picture a second installation across the lake region, with a different mission. [1, 2]

They belong to the same regional wartime landscape. Their locations, organizations, and later uses should remain distinct.

Before the atomic era: seaplanes and naval aviation

The military history archive describes a southwestern-shore seaplane facility commissioned in October 1942. PBY Catalina aircraft used the base for training and ferry operations. By 1944, its role had expanded to rocket training for carrier-based aircraft.

That earlier aviation history explains the infrastructure available when the postwar research mission arrived. This was an existing military facility with buildings and services, rather than a new scientific compound created from nothing. [2]

Why researchers chose the Salton Sea

Sandia’s institutional history records a December 1945 request for the Manhattan Engineer District to use the base. The site offered favorable testing weather and a below-sea-level setting, allowing ballistic work in dense atmospheric conditions.

Z Division, the Los Alamos organization from which Sandia emerged, began using the facility in 1946. The Navy transferred the site to the Manhattan Engineer District that November; it subsequently came under the Atomic Energy Commission. [3]

The local setting had acquired a national purpose. The shoreline was now connected to an engineering effort extending well beyond California.

What “atomic testing” meant here

Sandia describes the work as ballistic testing of inert, nonexplosive nuclear weapon designs. Its later institutional account also describes stockpile weapons being inspected and tested after removal of fissionable material. [3, 4, 10]

Engineers needed evidence about delivery and performance. A design’s connection to an atomic weapon did not turn every associated experiment into a nuclear detonation. Keeping those categories separate makes the history more informative—and avoids giving readers the wrong picture of what happened over the lake.

A working test station, not just a target

Sandia’s 2024 history describes an initial division of responsibility: the Army operated the base while Sandia directed technical and testing work. Teams restored Navy targets and installed camera pads. In 1947, the Atomic Energy Commission invested $3.5 million in improvements.

That account dates Sandia’s first test drop to March 12, 1947, and describes roughly 150 tests annually. Sandia assumed full base operations in 1950. Those milestones concern Sandia’s program; they should not be mistaken for the beginning of all military activity at the site. [4]

There was also a human community behind the mission. Sandia’s retrospective on its Family Day tradition records 300 participants associated with the Salton Sea Test Site in 1959. That small detail brings employees and families into a history otherwise dominated by institutions and dates. [8]

Explore the changing missions

Select an era to follow the transition from naval aviation to Sandia’s research program and later Navy testing.

Why Sandia moved its testing to Nevada

The conditions that made a useful range could change. Sandia’s 1950s history describes growing recreational activity, busier air routes, and a need for hard land targets. A larger, more isolated range offered advantages as the test program developed.

Tonopah’s first test drop took place in February 1957. Crews initially traveled there from the Salton Sea. Sandia’s 1960s chronology identifies 1960 as the transition to Tonopah as its permanent range; the Salton Sea program ended July 1, 1961. [5, 6]

For the shoreline, that marked the end of a major chapter. It did not mean every military use ended on the same day.

After Sandia: the parachute-testing chapter

The Navy’s 2013 historical review records the site returning to Navy control in 1964 for joint Navy–Air Force parachute tests involving land and water drops. In 1973, it became one of the National Parachute Test Range areas.

The same review describes later caretaker arrangements and changing responsibilities. It is a useful reminder to ask what a “closure” date refers to: the end of Sandia’s mission, a later test program, or a property action. [7]

Seeing the history in the records

Sandia’s 1940s archive includes original aerial photographs of the base in 1946. The modest buildings and bare ground offer a different impression from the dramatic imagery often associated with the atomic age. Look at the photographs alongside the directory page above: one records the built setting, while the other shows how the aviation facility was organized.

The featured image on this article is an AI-generated editorial reconstruction informed by that archival context. It illustrates the setting; its viewpoint and arrangement are interpretive. The original documents remain the evidence.

For exploring the region now, start with our Salton Sea guide and its established public destinations. Historical maps do not establish current access to former military property.

The test base adds another layer to the lake’s story: alongside wildlife, agriculture, and recreation was a place where the desert’s atmosphere, open space, and existing military infrastructure served an expanding research program.