History Pages: 43 - Petroleum in Santa Cruz, Then and Now
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Oil is an ever-present subject in the news: oil supplies, oil pipelines, oil spills, oil prices. To residents of bucolic Santa Cruz County, however, those stories mostly fall into the “somewhere else” category. Oil derricks like the ones in the photo at right were rare in the Santa Cruz area. Most locals don’t realize that, in the past, our county 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. Natives and Spanish padres found and used (mainly for water-proofing) 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 steam engines were invented that petroleum’s value began to rise.
Some of the oil-seekers in our county were drillers hoping to find underground reservoirs of liquid crude oil, as Drake had done. Those hopes were never realized, however, and oil drilling never became profitable. 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 the "gushers" found elsewhere, and the 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 their 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 - oil-impregnated sandstone - 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” (a popular term in those days) 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.
The county's largest bituminous rock 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 material 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 from the mine. Over 100 years later, stretches of the road paving remain in remarkably good condition (left).
The property subsequently passed through several hands, notably the “City Streets Improvement Company”. Neighboring property owners ran smaller mining operations, including I.L. Thurber and Henry Cowell (see map at right). In 2015, the flat-topped hill was in the news again, as the controversial site of a proposed residential development.
The north end of Pacific Avenue, beginning with the “lower plaza” at Front and Water Streets, was where downtown asphaltum paving began. An 1886 photo shows the 2-year-old Swanton House Hotel facing a newly-paved Front Street, with a still-unpaved Water Street (notice the wagon-wheel ruts) on the left. This location is where the main Post Office stands now.
Many downtown residential streets got asphaltum sidewalks, with curbs of roughly-cut local stone, to replace decomposing wooden planks. The change can be seen in two photos of the Hihn mansion, on Church Street. The earlier photo (left) shows a board sidewalk. In a later (1900) photo (right), the old boards have been replaced with a smooth asphaltum surface, retained by a cut-stone curb (the street itself remained dirt).
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 State Park. The photo at left shows the black asphaltum on the left, abutting a newer concrete surface. By the mid-1890s, the mines 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.
- Gary Griggs article “Hydrocarbons in the Hills”, Seymour Center.
- Frank Perry, "Lime’s Sister Industry: Bituminous Rock", Lime Kiln Chronicles Spring 2013 issue.