Oil is a popular subject in the news these days: oil supplies, oil pipelines, oil spills, oil prices, "fracking". To those of us in bucolic Santa Cruz county, however, those stories mostly fall into the “somewhere else” category. Most locals don’t realize that our county has had its own encounters with petroleum.
Edwin Drake’s 1859 discovery of oil in Pennsylvania set off a new kind of “gold rush”, and prospectors in California jumped in. The presence of petroleum in Santa Cruz County had long been known. Ohlone natives and Spanish padres found and used natural seepages of oil and asphalt leaking out of layers of “bituminous rock” that surface along the north coast. The problem was that only small quantities could be obtained in this way, and uses for it were also limited. It was only when kerosene and oil -fired boilers for steam engines were invented that oil’s value began to skyrocket.
The first oil-seekers here were drillers hoping to find underground reservoirs of liquid crude oil, as Drake had done. These hopes were soon dashed, however, and oil drilling tailed off. Others had the idea of extracting oil from the bituminous rock by crushing the material and heating it to make the oil flow so it could be separated. The laborious technique worked, but couldn’t compete with cheaper production elsewhere, and this effort also failed to turn a profit.
In the 1880s, a new idea began to take hold. The people of Santa Cruz were, like other urbanites around the state, getting tired of slogging through mud all winter and clouds of dust all summer. They began to explore the feasibility of paving the city streets and sidewalks.
One candidate was a byproduct of the lime industry. Local limestone quarries could produce crushed rock that would provide a semi-durable road surface, especially if used in the “macadam” technique developed in England. For whatever reason, however, macadam roads never caught on locally in a big way. It could be that the limerock was more valuable as feedstock for the kilns than as road paving.
For bituminous rock, the ROI calculation became more favorable. The same quarrying and heating techniques already developed for oil extraction could be used, but simplified. After moderate heating, the softened, sticky mass of “asphaltum” was simply dumped on the road, spread around and flattened by tamping and/or rolling. Similar methods are still used with small-job modern asphaltic paving - we all love following one of those smoking asphalt-mixers on the road.
The county's largest bituminous rock quarrying operation was originally known as the “Walrath mine”, in the coastal hills northwest of Santa Cruz, where the entire top of one large hill was removed to get at the layer of bituminous rock below. The removed earth was pushed over the sides of the hill, and can still be seen today. A wagon road was built to haul the rock down to the Coast Road and, at some point, was paved with asphaltum. The property subsequently passed through several hands, notably the “City Streets Improvement Company”. Neighboring property owners ran smaller quarrying operations, including Henry Cowell (see map).
Recently, I had the opportunity to visit with Ray Gwyn Smith, who lives nearby. She was kind enough to point out the location of the Walrath mine to me, and to share with me her research on its history. The now-flat-topped hill has recently been in the news again, as the controversial site of a proposed residential development.
Pacific Avenue, beginning with the “lower plaza” at Water Street, became the first downtown street to receive the new asphaltum paving. An 1892 photo of the Flatiron building shows a paved Pacific Avenue on the right and a still-unpaved Front Street (notice the wagon-wheel ruts) on the left.
Many residential streets to the west of Pacific Avenue and on Beach Hill got asphaltum sidewalks, with marble or quartz curbstones, to replace aging wooden planks. Another popular use for the new paving material was for factory and farm building floors. One of the best-preserved asphaltum floors can be seen in the horse barn at Wilder Ranch.
By the mid-1890s, the quarries were producing enough bituminous rock that it became the county’s leading mineral export, edging out lime in dollar value for several years. Much of this product went to San Francisco, where it was reportedly used to pave Market Street, among others.
Inevitably, advancing technology and changing markets led to a decline in competitiveness for the bituminous rock industry. Less expensive methods for producing asphaltic paving were developed, while concrete became the material of choice for sidewalks. The asphaltum streets and sidewalks disappeared, and a once-important chapter of Santa Cruz history was mostly forgotten.