Archaeological tests in 1992 suggested that evidence of the McCoy House, in the form of mortared brick foundations, had survived under the parking lot that capped the site (Wheeler and Felton 1992). Artifacts representing previous occupations were also present, although no clearly identifiable remains of earlier buildings were noted.

In 1995, more extensive excavations were undertaken to provide architects with the information needed to design the McCoy House reconstruction, as well as to recover data likely to be impacted by construction (Felton 1995).

As soon as pavement was removed, foundations of the McCoy House began to appear, as did the foundations of an earlier adobe building, which may have belonged to Maria Eugenia Silvas. The locations of the 22 by 29-foot adobe foundations, as well as those of the McCoy House, are shown in Figure 2. The foundations of the McCoy House overlap the earlier feature, clearly showing the 2 buildings occupied the site at different times. Instead of the more commonly used river cobbles, the adobe footings are made of kiln wasters, which are large, pumice-like chunks of over-fired floor and roof tiles, presumably discarded at an unknown kiln location. Portions of at least 2 other kiln waster footings were also found elsewhere on the site, although they had been disturbed by later construction.

Most of the area inside the footprint of the McCoy House was excavated in 1995. The McCoy House had preserve earlier strata that are probably contemporary with the adobe. These relatively thin deposits were excavated stratigraphically, and proved to be rich in artifacts, some of which are described below.

Near the bottom of the deposit, we also discovered another group of intriguing archaeological features. These are a series of small post holes which could be attributed to several kinds of structures, from simple racks or covered ramadas, to fully enclosed jacal buildings. Such construction methods were commonly used to erect buildings quickly at new mission and presidio sites, as well as for temporary buildings elsewhere. Although we have recorded over 20 of these features to date, we have not been able to trace the outline of a specific building, or establish with certainty that the postholes are contemporary with the adobe foundations.