Tracking down a quarry, with questions still unanswered

Tracking down a quarry, with questions still unanswered

Tracking down a quarry, with questions still unanswered
The most probable location for the quarry that spawned the name Old Quarry Rd. in Pleasant Hill was the A.E. Slater/Serra Brothers quarry .6 miles south of Pacheco. (Photo courtesy Contra Costa History Center)

CONTRA COSTA COUNTY—The quest for a quarry began with a query: “Where is the quarry for which Old Quarry Road in Pleasant Hill is named?”

It took a team of volunteers to come up with the answer.

With the Contra Costa County History Center closed because of the COVID-19 virus, we have to rely on computer data – mostly from the Contra Costa County Historical Society’s (CCCHS) online database. We found 15 quarries in Contra Costa County in CCCHS records.

Our first supposition, after driving Old Quarry Road, was that it might be under Diablo Valley College (DVC). Our director perused the CCCHS photograph files and found a picture of DVC with a quarry visible to the north. Information filed with the photo revealed that the Serra Brothers’ Slater Quarry had been on Camelback Road near Pacheco.

Our photo file expert Janet joined the search and came up with more quarry pictures. Positioning these in conjunction with a map of the same area, she concluded that the quarry we were seeking would have been behind today’s Target.

Another volunteer suggested that Shadowood Park might be part of the quarry because of its peculiar shape. The park is across Grayson Creek from the rear of Pep Boys, closer to Pacheco.

A.E. Slater

It seemed that the quarry of our quest was probably the one owned and operated by A.E. Slater beginning in 1906. The Serra Brothers later ran the quarry, which is six-tenths of a mile south of Pacheco. More exactly, according to Google, its location was 37 degrees 58’ 31” north, 122 degrees 4’ 14” west, give or take 500 meters.

Most of the rock that was produced was used for highways. The rock is a very soft, friable sandstone used for macadam, according to the website Stone Quarries and Beyond, compiled by Pat and Peggy Perrazo. The quarry was intermittently active from 1906 and definitely active 1940-1958.

Bordering the locale are the Camelback Townhouses built in 1960 and Choice in Aging, an adult day health-care program accessed from Golf Club Road.

There is still a big question as to why this location was chosen for a quarry. And, it isn’t located on Old Quarry Road.
Please share any information you may have on this subject with the History Center at We would be happy to hear from you.

A History Note is presented by the Contra Costa County History Center, 724 Escobar St., Martinez, using materials from the society’s collections. The History Center is currently closed due to the coronavirus. For more information, visit