Phoenix Hohokam

Welcome to my first effort at sharing my experiences in the field as an archaeologist working in the desert southwest. This is my 21st season working in cultural resource management and my 11th in the southwest. I am extremely grateful to have such an interesting, engaging and exciting job. I get to travel all over the desert, explore and often excavate in remote places, and meet all sorts of people.

My last job just wrapped up (January 20) with PaleoWest in Phoenix about a mile south of the Salt River. It was a Hohokam site with at least 2 temporally discreet occupations- the latest Classic or possibly Late Classic (1150-1450AD).  The earlier likely Sedentary (900-1150AD) but this is speculative until carbon dates and pottery types are returned.

Excavation of test unit- extramural work area in the foreground

The photo above shows me excavating a test unit within a feature in an effort to define possibly buried habitation surfaces. The stratigraphy within the backhoe trench I'm standing in displayed alternating coarse sandy and silt loam deposits. Mixed in with these were flat laying sherds and areas of gray-brown sediment- typically a sign of a habitation surface, often a pithouse.

The area exposed by mechanical stripping in the foreground was noteworthy, defined as an extramural work area. There were 6 pits identified and excavated (2 are visible in the foreground, one is left-cnter), at least 2 of them were likely pits for mixing adobe. In front of me are 2 hearths, full of ash and heavily oxidized. To the right center in the photo is a large cobble set upright in the ground- this was defined as an anvil, possibly for leather working.

Extramural work area with 5 pits to the left

Dating this area will have to wait for the evaluation of pottery types and carbon dating.  One Red-on-Buff large bowl sherd, likely Santa Cruz phase (875-950AD), was recovered from the fill above the area.  However its proximity to the surface and its depth relative to a nearby Classic period adobe-walled structure suggest that this extramural work area was also Classic period.

Just to the north, at a similar depth, we encountered an adobe walled structure with at least 2 hearths. The structural morphology and ceramics recovered (redwares) strongly suggest an occupation between the Soho and Polvoron phases (1200-1450AD).  These structures are relatively rare and were contemporaneous with the construction of large platform mounds in the Phoenix basin as a well as a likely hierarchically stratified social structure.  My co-worker Dean exposed about a third of a Red Ware bowl resting on the floor. The floor assemblage also included 2 small metate fragments. While excavating the rock-hard fill from within the structure I noted a high density of rounded river pebbles that initially seemed out of place. Eventually I concluded these must have been used to reinforce the adobe walls- and in fact I did expose a section of the wall with embedded pebbles- a satisfying moment.

Control unit exposing the floor of the Classic/Late Classic Period house

Classic/Late Classic Period house

While this was the only Classic period structure we encountered on the site, we excavated several pithouse structures that likely represent a Sedentary period occupation.  In most cases these were defined at stratigraphic levels markedly deeper than the adobe-walled house. Morphologically they differ from the Classic period structures in several ways- they tend to be bean-shaped in plan view with defined elongated entryways, rather than the rectangular shape in the Classic. Also the living area was excavated into the underlaying sediments and included an overarching superstructure of brush and adobe- hence the name "pit"house.  

Prior to excavation the faint outline of the heavily burned pithouse could be seen in plan view, with the entry pointing north.

Pithouse pre-excavation

Probably the greatest challenge when excavating these features is defining the living surface. This is a complicated task for several reasons, assuming preservation of the structure did not include a plastered floor, which wasn't present in all houses.  If the structure was remodeled there may be multiple living surfaces.  Often the sediments overlaying the surface are very similar to the composition of the floor itself.  Clues to finding the surface include artifacts that cluster at the same elevation, "flat-laying" artifacts, particularly ceramic sherds, or finished artifacts like metates or ceramic vessels. The presence of a hearth or a pit is also a good way of determining you've reached the floor. If the house burned, removing the sediment that includes charcoal flecking will often expose the living surface.

None of the ceramics recovered from the excavation of the pithouse could be identified as diagnostic, perhaps some will show up in the lab. Several olivella shell beads and 2 perforated thin shell discs were present- a long way from their homes in the Sea of Cortez.

The pithouse contained a hearth in the usual spot just inside the entry, and a subrectangular pit in the southeast corner. The pit fill was nearly identical to the fill present in the rest of the house suggesting it was open, and likely empty when the house was abandoned. There was ample evidence that this house burned, plenty of gray ashy sediment just above the floor and charred structural remains here and there. The lack of a floor assemblage suggests the house did not burn while occupied- perhaps the house was burned intentionally as part of a renewal or mortuary ritual.

Pithouse post-excavation

Hohokam archaeology fascinates me. After over 70 years of fieldwork in the region sufficient data exists to allow the exploration of nearly any part of their culture. Settlement patterns, subsistence strategies, long range trade networks, ritual behavior- all are accessible for synthesis and interpretation.  Every project adds to the corpus of data while raising new questions and suggesting new directions.  Our site, AZ T:12:413 (ASM), contained at least two temporally discreet habitations, cremations and inhumations, a likely canal segment and numerous thermal and extramural features. It was a pleasure to excavate.