Park Boulevard sweeps through steep, rocky Dimond Canyon with just one isolated, incongruous building along the way: a big church in a space carved out of the cliff. That hole in the wall is a former rock quarry that’s had several names, and ups and downs, since the late 1800s.

In the early days the growing city of Oakland demanded rock, and the hills around present-day Piedmont, with good stone and good access to the market, had plenty to provide. Although a few large quarries dominated, other operators found their opportunities, and some time before 1900 one of them, probably the Ransome Concrete Construction Company, opened a quarry on Henry Heyland’s property overlooking Dimond Canyon, along the old county road that once served the redwood trade. The quarry’s cheap crushed sandstone, not premium stuff but good for many uses, brought its landowner a good income, about $100 a month.

Heyland died in 1904, and soon the quarry’s ownership changed. In 1906 The Structural and Industrial Materials of California, published by the state mining bureau, included this entry:

Diamond Cañon Quarry (Heyland Quarry); Hutchinson Company, 401 Fourteenth Street, Oakland, owner. Four miles from Lake Merritt, on Diamond Cañon road, East Oakland. There are two quarries; in the upper one the rock is a hard, medium-grained, gray sandstone; in the lower quarry face in the cañon, 100 yards below the road, is a flinty, dark-colored, metamorphosed sandstone. The crushing plant is abandoned and badly out of repair.

In 1907, when the residents of Piedmont voted to incorporate as a city, most of the Heyland quarry property became part of Piedmont. Today the city line just includes the church buildings, and in a geographic oddity Piedmont’s border bulges across Park Boulevard here.

Heyland’s estate sold the land in 1908 to Frank “Borax” Smith, whose firm the Realty Syndicate owned most of the high hills. The old canyon road was the key to developing Smith’s lands with residences in coming decades. He told the Tribune he intended to shut down the quarry “in order to prevent the street in front of his property being cut up by heavy gravel wagons.”

For the Realty Syndicate, the need for cash flow often overrode anything else. For whatever reason, need or greed, Smith soon relented, and in 1909 when the papers reported a blasting accident that killed three workers, the Piedmont Paving Company was operating the quarry while Smith continued to own the land.

In 1910 the following photo was taken from due south across the canyon, high on Leimert Boulevard.

Every part of this image is interesting. First, it shows the hills in their unforested state, the way the Ohlones maintained them and the Mexicans left them. For me as a geologist, it shows the change between Franciscan melange, with its lumps of exotic rock set in a fine-grained matrix, on the right and the more homogeneous Franciscan sandstone on the left. The contact between them is mapped as a thrust fault, and I fancy a hint of it across the back wall of the quarry although that wouldn’t match the geologic map here.

For local historians, it shows the old county road before Park Boulevard was upgraded as well as the road that became Estates Drive running over the hilltop. It shows the upper and lower workings mentioned in the state report, and it shows the huge piles of waste rock that were dumped into Dimond Canyon without arousing any complaint.

A few years after this photo was taken the quarry was operated by the construction firm of Bates, Borland and Ayer (Charles D. Bates Jr., Archibald “Archie” Borland Jr. and Richard B. Ayer), which became Bates & Borland in 1917 after Ayer left. People usually just called it the Bates quarry. Work there went on into the 1920s, a time of vigorous construction, but it appears to have been abandoned by 1929, when a 13-year-old boy died there in a fall.

Changes came in the 1930s. Starting in 1932, Park Boulevard was upgraded through Dimond Canyon to the state we know today. As the Tribune put it,

“The artery, at present a narrow, winding road skirting the upper reaches of Dimond Canyon, is to be transformed into a splendid boulevard, measuring 48 feet from curb to curb. . . . Besides being widened over its entire course, the present road will be straightened. In line with this straightening process the road will cut through part of the large quarry situated between the junction of Park boulevard and Mountain boulevard.”

This photo from the paper shows the plan as well as the state of the road at the time. The three arrows point to where concrete trestles (“side-hill bridges”) were built, which still hold up the road today.

The old quarry was a ticklish part of the project; the Tribune reported city engineer Walter Frickstad as saying “that this slide is the hardest engineering problem on the whole job, but he declared that enough rock and dirt may be diverted here to strengthen the hill by filling up the shallow ravine below it.”

Much of that rock must have come from roadcuts on Park Boulevard downhill from the quarry. The photo shows that the excavation was larger than in 1910 and had reached roughly the size it is today.

In the mid-1930s the gun club for the police and fire departments had a shooting range in the quarry, until the neighbors across the canyon complained. The range moved up to Chabot Regional Park, where it remained into this century.

In 1947 “the old Bates and Borland quarry” was proposed for a land swap between Oakland and Piedmont “so a multiple family dwelling — outlawed by Piedmont zoning laws — could be built on it.” That didn’t happen, but eventually the Zion Lutheran Church, founded in 1882, moved from its historic building at 12th and Myrtle to new digs in the quarry in 1954.

The quarry walls must have been cleaned up at that time, but today they’re being stabilized again. Fortunately the top doesn’t seem to be retreating into Estates Drive, but eventually, after the next big earthquake if not sooner, it will need reinforcing.

Down in the canyon, the waste rock from the upper and lower quarries spilled all the way to Sausal Creek. Proposals were made more than once to dam the stream with the rubble to create a swimming hole. That never happened, but that stretch of the canyon was a nuisance for many years, with people shooting guns and poison oak everywhere. In 1957 Park Commissioner William Penn Mott Jr. proposed that the city turn the land into a golf course leased to a private operator, part of a scheme that included a fancy restaurant up in Joaquin Miller Park. In 1958 the architect in charge called the site “the doggonedest challenge to a course builder I’ve ever seen.” Finally the old quarry tailings were used to cover the stream outright, laying the ground for the Montclair Golf Course, which opened in 1961.

This entry was posted on 10 November 2025 at 7:54 am and is filed under Quarries and mines. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.