March 2004 - Society for California Archaeology

30
Articles
Early Investigations: Predictive Models
and Archaeological Survey
The site of El Presidio de San Francisco is unusual in that
both the quadrangle site itself and the surrounding landscape
have been managed since 1847 by Federal agencies. It thus
provides an unparalleled opportunity to investigate the
presidial settlement from a holistic perspective, one in which
the presidio’s main quadrangle is viewed as the military,
economic, and administrative nucleus of a much broader
network of ancillary fortifications, residential areas,
infrastructure facilities, and agricultural and resource
extraction operations.
My preparations for the Tennessee Hollow Watershed
Archaeology Project began in 1996. Then a graduate student
at UC Berkeley, I approached National Park Service
archaeologist Leo Barker with a proposal to conduct an
archaeological survey of lands within the Presidio of San
Francisco to try to identify the remains of these extramural
activities and households. Working from Barker’s models of
predicted locations of archaeological resources at the Presidio
of San Francisco (Barker 1989, Barker 1992), we identified
the valley floor of the Tennessee Hollow Watershed as a
promising area for further research.
The Tennessee Hollow Watershed is a sheltered valley
located immediately east of El Presidio de San Francisco’s
main quadrangle. Tennessee Hollow is rich in both historical
and ecological significance. The year-round presence of fresh
water supports diverse plant and animal communities. During
the Spanish and Mexican periods, the valley floors were used
for farming and grazing, and the serpentine bedrock outcrops
on some of the watershed’s slopes were quarried for stones
used to make the foundations of adobe buildings at El
Presidio de San Francisco.
Typical of other areas in the present-day park, the valley
floor today is a patchwork of intensely developed residential
areas interspersed by heavily vegetated open space covered
with brush, forest, and grasslands. Earlier archaeological
survey at the Presidio of San Francisco found that surface
visibility in the park is near zero (Ivey 1991). Ultimately, I
chose to use shovel probe survey as a method to detect
colonial-era sites.
The shovel probe survey of the valley floor was
completed in the summers of 1997 and 1998, with students
from the University of California, Berkeley serving as field
crew (Voss 1999). (Figure 2) Our methods were
straightforward: having divided the valley floor into several
survey zones using both natural and cultural features, we
excavated shovel probes at the nodes of a thirty-foot grid.
Each probe was excavated to a diameter of twelve inches and
to a depth of twenty-four inches; excavated soils were
screened through 1/8” mesh to recover any artifacts that
might be present. Because of the indurated, clay-rich soil
found in the valley floor, this process was very labor-intensive
– on average, each survey crew member was able to cover
only about 0.15 acre per day. Despite this slow pace, the
shovel probe survey method was highly effective in
identifying the locations of near-surface deposits that would
not have been detected with the naked eye. In all, three
Spanish-colonial/Mexican period deposits were discovered
(Figure 3). The general location of one residential area – El
Polín Springs – was known through historic documents, but
the other two deposits – named the MacArthur Avenue
deposit and the Lovers Lane Bridge deposit – are not
recorded in any historic sources and would not have been
discovered without systematic subsurface survey.
Artifacts collected from the shovel probe survey indicated
the research promise of the deposits. They included many
artifacts typical of Spanish-colonial deposits: construction tile
tejas and ladrillos, household ceramics such as majolicas,
galeras, and British creamwares and pearlwares, wrought
ferrous artifacts like nails, spikes, and hinges; and bottle glass.
In addition the survey recovered artifacts typically associated
with colonial-era Native Californian lifeways: flaked stone
and flaked glass artifacts and debitage, fragments of
groundstone tools, glass beads, and cut and shaped shell
artifacts.
Current Excavations:
Reconstructing Life in the Valley
The Tennessee Hollow Watershed Archaeology Project is
currently scheduled for five years. Our efforts are centered on
two of the three deposits discovered during the 1997-1998
survey: El Polín Springs and Lovers Lane Bridge
(unfortunately it appears that much of the MacArthur Avenue
deposit has been disturbed by modern construction, limiting
its research potential). We plan to excavate for two summers
at each site – first, a series of test excavations, followed by
areal exposures and data recovery excavations of the deposits
encountered by the test excavations.
El Polín Springs
We began this research at El Polín Springs (Figure 4). El
Polín is a bowl-shaped valley located at the southern end of
the watershed, with at least three springs that emerge from
the valley slope and gather into a small stream. This
historically-important water source is located only a short
five-minute walk from the main quadrangle along the trail
that used to lead from the Presidio to Mission San Francisco
de Asís (Mission Dolores).
As noted above, El Polín Springs is the only deposit in the
valley for which historical documentation exists. From
archival studies, we know that by the 1810s, El Polín had
become the home of a large extended colonial family headed
by Marcos Briones and at least three of his adult daughters,
María de Guadalupe Briones (married to Calendario
Miramontes), Juana Briones (married to Apolinario Miranda),
SCA Newsletter 38(1)