Texas Archaeology Month at the Alamo - Week Four

Tiffany M. Lindley, PhD, RPA, Archaeologist
October 25, 2021

For the final week of Texas Archaeology Month, we want to showcase a component of archaeology that may not be as flashy as an artifact but is equally important: the archaeological feature.

What is an archaeological feature?

A feature is an immovable, physical element of an archaeological site. Some features, like a hearth or roadway, can alert archaeologists to human activity in the absence of artifacts. However, artifacts and features are often found associated with one another. Features can be large, like a structural foundation, or small, like a posthole, which is a small, round stain in the matrix that forms when a wooden post decomposes or is burned. If left unprotected, archaeological features can be heavily impacted by environmental conditions and modern activities. Features are important because, unlike artifacts, features are found in the location where they were left by previous human activity and provide insight into prolonged use of a site.

Structural foundations are a common feature encountered by archaeologists. Structures built in the past are frequently torn down to make space for new development. However, sometimes the entirety of the structure is not removed, and remains of the foundation may be left intact. One reason this might happen is that over time there is an accumulation of soils and/or debris that builds over the original surface level, thus covering any remaining portions of the feature. Any element at a lower elevation will likely experience a higher accumulation of soils, sometimes resulting in buried portions. As time passes, the feature can become buried entirely.

Structural foundation with soils inside architectural stones
A portion of a structural foundation encountered in the vicinity of the Alamo complex, notice how the soils have buried the architectural stones

When a historical archaeologist encounters certain features, they compare it with any accessible archival data, like old photos or maps. This will help determine if the revealed feature is part of a known, historic structure.

A circular, stone-like feature, visible in the photo below, was revealed by archaeologists during excavations north of the Alamo Church. Archaeologists utilized archival research (see maps below photo [Nelson 2009]) to suggest that this circular feature is a possible watchtower during the time which the Alamo served as a fort. There is a circular element depicted on both maps in the proximity of where the archaeological feature was revealed. In this example, archaeological and archival evidence worked in conjunction to aid in interpretations.

Foundation revealed inside excavation unit
Possible watchtower foundation revealed during excavations, photo facing south
1846 Map depicting the Alamo grounds
1846 Map by Edward Everett depicting the Alamo grounds
1848 Plan Map depicting Alamo grounds
1848 Plan Map by Edward Everett depicting Alamo grounds after U.S. Quartermaster began using site
Two archaeologists working inside an excavation unit
Archaeologists mapping a portion of the foundation inside the Church

Visitors to the Alamo in late 2019 and early 2020 may have noticed the excavations associated with some very important features: the foundations of the Long Barrack and Church. Excavations were conducted in support of ongoing preservation efforts. The revealing of the foundation was critical because it allowed the preservation team to observe the original construction techniques, as well as identify the best preservation practices moving forward.

During modern construction activities in and around historic sites, often an archaeologist is present to monitor the excavations. This is especially true of culturally rich cities like San Antonio. The next time you are driving around town and see construction activity, there might be a vigilant archaeologist on site checking for any historical features like an old foundation.

While this post concludes Texas Archaeology Month, archaeology at the Alamo is not over. We hope you continue to check back for more updates on all of the work happening at the Alamo!


Nelson, George
2009 The Alamo: An Illustrated History, 3rd edition. Aldine Press, San Antonio, TX.