San Francisco West Approach
Unearthing San Francisco’s Accidental 19th Century Time Capsules
Neither
the stifling heat of summer nor the bogged down wet and slippery
mud of winter kept ASC archaeologists from completing work on the
largest excavation undertaken in San Francisco. It was all part
of the Caltrans seismic retrofit of the West Approach to the San
Francisco-Oakland Bay Bridge. The result of a long planned research
effort that targeted six city blocks, it started back in May 2001
and lasted into January 2003.
Specific excavation sites were chosen based on several years’ historical
research. 
Downtown commuters were kicked out of their parking lots
under the elevated section of Freeway 80 which probably didn’t endear
us, Caltrans, or Balfour Beatty, the international construction
firm we worked with, to the hapless drivers. Large areas, and sometimes
all, of a city block were fenced off. Security guards were employed
to keep the bad guys from looting features as we dug. Archaeologically
Sensitive Areas (ASAs) were marked out and the homeless drunks lying
paralytic on the asphalt politely escorted off the block. Sticking
their heads over the fence the homeless were to be our most frequent
spectators, advising the odd passerby (they can be very odd in San
Francisco) on the progress of the excavation. We were later to be
thankful to them when the field director drove off the site with
his laptop sitting on the lowered tailgate of his truck. A group
of homeless people recovered it after a following car had run over
it. They were camped on the sidewalk discussing the potential impact
on the hard drive that had miraculously survived when the hapless
field director stumbled upon them. He had been roaming the streets,
looking for his lost computer. Data rescued and the finders rewarded,
he bade farewell to his benefactors thinking unemployed Silicon
Valley dot-commers had to wind up somewhere and wasn’t it lucky
for him they wound up where they did.
A hardy and dedicated crew then set out to uncover and explore the
inadvertent time capsules left behind by the earliest and often
forgotten inhabitants of this city. These were the pits, privies,
and wells in residential, commercial and institutional back yards.
When no longer needed, after water and sewer lines were hooked up,
they became convenient receptacles for all sorts of unwanted household
materials, not counting objects accidentally dropped. And even back
then, no-one wanted open pits in their backyards for children or
older family members to fall into, so these features would be rapidly
filled and usually sealed with a clean layer of sand, turning them
into the time capsules they were never meant to be. When combined
with census and city directory data, which often enabled the residents
to be identified across a time spectrum, the excavation opened a
window into San Francisco’s past with a view from an angle quite
different from that provided by written documents alone.
There were fourteen city blocks included in the project area to start with. But detailed research and the expectation that modern construction would have destroyed remnants of old San Francisco saw that number narrowed to six. As for the other eight blocks that didn’t make the cut (almost literally), pre-field study indicated there was nothing left in the impact areas due to modern construction or else there wasn’t enough of a project impact to warrant investigation. Strolling through the city you could have walked past the sites a few blocks from Market Street and the financial district and not known what was going on behind the chain-linked fence that was covered with black plastic sheeting to keep the dust in. To the world outside, it must have looked like any other downtown construction job.