Central Anza-Borrego: US Gypsum Company Quarry

A Crack in the Fish Creek Mountains at the Gypsum Quarry

The United States Gypsum Corporation quarry is at the south end of Split Mountain Road, 8 miles south of Ocotillo Wells on Highway 78. The quarry sits in a long narrow valley that runs from north to south into the Fish Creek Mountains.

The photo above shows of the west wall of the valley. The large crack in the middle of the red rock wall is on an earthquake fault. The light-colored peak to the left is gypsum.

The picture at left was taken from the west side of the quarry where USGC is constructing a road to the top of the ridge to get at more gypsum. Gypsum is mined from the top of the hill to the bottom.

At present, the mining takes place on the east side of the valley. USGC has been working from left to right (north to south) in the photo. The stair-steps are a result of the mining. Eventually, they will be smoothed over and replanted. The mines in the photo date back to the 1950s when mining was a lot less efficient than it is today.

Shown above is the quarry plant, looking toward the northeast. The building to the right of center holds the crusher. Large dump trucks bring the rock to the other side. The rock is crushed and sent to the storage building on a conveyor belt. They can store enough rock for 10 train loads. The train enters the picture from behind the mountain at the top right. It circles around the hill on the left and enters the quarry facing south.

Unsuspecting illegal immigrants sometimes follow the tracks to get to Los Angeles, but they end up at a dead end out here instead, or else they walk blindly into the hills.

This is on the east side of the quarry. The dark hills in the background are weathered granite. The mounds in the middle have been core drilled to tell how much gypsum they contain and to evaluate its quality. Quarry personnel say it isn't as easy as it looks to climb one of these mounds and insert dynamite and blast it.

The rocks in the foreground need to be evaluated. The operator of the scoop shovel (a million-dollar scoop shoven) has to be able to tell gypsum from other rocks. Other rocks can be harder than gypsum and clogs the equipment, reducing efficiency.

One of the rocks found here is alabaster. According to quarry officials, Indians of long ago mined it and made it into utensils for cooking and eating. Sculptors call at the quarry and USGC gives them rocks that the sculptors can use but which USGC can't.