It is not known exactly what is going on in this aerial photo, which was shot by Gary Thornhill on Nov. 21, 1990, during a helicopter ride with his stepdaughter, pilot Christina David. The apparatus on the truck at center appears to be a drilling rig.

The Bermite Powder Co., and Halifax Powder Co. before it, manufactured explosives, flares and small munitions in Saugus, on a roughly 1,000-acre parcel just southeast of Bouquet Junction, from 1934 to 1987. The company and the property played an important role in the needs of the U.S. military during World War II, the Korean War and the Vietnam conflict — and in the development of Newhall, establishing a row of company homes along Walnut Street in the 1930s. After World War II, Bermite formed a subsidiary, Golden State Fireworks, which manufactured fireworks on the property.

The munitions and fireworks operations left more than 275 known contaminants behind, some of which percolated into the groundwater below the property.

Bermite was acquired in 1986 by missile maker Whittaker Corp. Around 1989, plans were made for the area to be developed into a 2,911-unit residential community to be called Porta Bella. Whittaker sold the Saugus property in 1999, just before Whittaker was acquired in a hostile takeover.

About the photographer: Photojournalist Gary Thornhill chronicled the history of the Santa Clarita Valley as it unfolded in the 1970s, ‘80s and ‘90s. From car races in Saugus to fatal car crashes in Valencia; from topless beauty contests in Canyon Country to fires and floods in the various canyons; from city formation in 1987 to the Northridge earthquake in 1994 — Thornhill’s photographs were published in The Los Angeles Times, The Newhall Signal, The Santa Clarita Valley Citizen newspaper, California Highway Patrolman magazine and elsewhere. He penned the occasional breaking news story for Signal and Citizen editors Scott and Ruth Newhall under the pseudonym of Victor Valencia, and he was the Santa Clarita Valley Sheriff Station’s very first volunteer — and only the second in the entire LASD. Thornhill retained the rights to the images he created; in 2012, he donated his SCV photographs to two nonprofit organizations — SCVTV and the Santa Clarita Valley Historical Society — so that his work might continue to educate and inform the public.