Douglas Mangum has been excavating the San Jacinto Battlefield and adjacent areas to the site since 2003.

Mangum, a project manager for Moore Archeological Consulting of Houston, said their project is the first organized metal detecting survey of the battlefield.

San Jacinto, located in Deer Park near Houston, was the location of the battle between the Texas patriots and the Mexican army of General Antonio Lopez de Santa Anna on April 21, 1836.

The battle won Texas its independence from Mexico and established the independent Lone Star Republic.

Mangum said the battlefield and adjacent areas had not been professionally excavated prior to 2003.

“People have done undocumented collecting and there have been archeological excavations out there that have been of the more standard type, not using metal detectors,” said Mangum on Thursday night at the Walker Education Center.

He gave a presentation on the archeological findings of the battlefield so far as part of Texas Archeology Month sponsored by the Sam Houston Memorial Museum.

Mangum said they have a permanent staff of seven to eight, but they also work with other groups such as the Texas Archeological Stewards Network and Sandy Rogers of Huntsville who is a member of the network.

Mangum said his group is currently “covering an area where we discovered a large number of Mexicans surrendered and the rest of it is actual parts of the combat.”

While the area has yielded “plenty of very interesting individual items,” Mangum said “for us, the most fascinating part is how it all pieces together, particularly the surrender site. That was completely unexpected.

“The site is more than a mile away from the main battlefield. We never expected to find an intense concentration of artifacts that far away from the battlefield.

“We assumed everybody would have scattered, but by looking at the placement of the artifacts and showing how they relate to treelines and the topography we were able to identify this as a very specific historic event that happened a mile and a half outside the main battlefield.”

Mangum said they are interpreting the wooded area as the surrender site “because almost everything that is found there seems to have been simply dropped in place as opposed to being the result of people dropping things during combat.”

While Santa Anna was captured by himself miles away from the site, Mangum said “this was a large body of Mexican soldiers under the control of a handful of officers, who managed to round them up and convinced them that ‘if we surrender as a group maybe the Texans won’t kill us.’ ”

“They had them drop whatever weapons they still had, take off the more obvious uniform bits and pieces they still had, leave those behind, walk out of the treeline and show themselves in a large group to a small group of Texans and ask for surrender,” Mangum said. “That is basically what happened.”

Several items excavated from the surrender site were displayed Thursday night, including four bayonets, stirrup, rifle shot, gun tool, ramrod, buttons, spur and fire musket balls.

Of the bayonets, two were found within five yards of one another.

Mangum said the Sam Houston Museum is currently displaying five artifacts found in 2004.

Mangum said no muskets were found at the surrender site because the Mexican soldiers discarded them on the way there.

“The only reason they had bayonets was because if your bayonet was not already attached to your musket, it was probably in a holster,” Mangum said. “Some of the guys managed to make it through the brush and the mud and swamp with those still in place.

“That was not because they were trying to hold onto them, but because they didn’t want to take the time to take them off and throw them away. It wasn’t until they had the time to slow down and stop that that happened.

“That is our theory. It’s always theory.”

Mangum said they plan to excavate the battlefield area “as long as they will let us. We’ve covered less than one percent of the actual battlefield itself — the part that is part of the state historic site. Within that context, there is still a lot to be done.

“Some of those areas have already been heavily impacted by construction, but there are a lot of areas that haven’t been and we need to look at them.”

Mangum said the artifacts that have been discovered have been located less than a foot underground.

“We don’t know whether that’s because that is the limit of the metal detectors we are using in the particular soil we are working in, or whether that is simply as deep as they are.

“We have found a few items that were maybe a foot and a half deep, but that is the exception rather than the rule.”

Mangum said the new standard in professional battlefield archeology is using metal detectors, but “with the same control we would expect from any other archeological excavation.”

“While we may dig a lot of holes, we still have complete control of where those artifacts are located by downloading them into a computer which can interpret those locations and plot them.

“We know within an inch or two exactly where that artifact came from. After we’re done with that interpretation, we end up passing them on to the Texas Parks and Wildlife Department.

“They will curate them, some will end up in museums or used for research, some will end up just artifacts because they are not particularly spectacular.”

Mangum said his group has learned that in the case of the surrender site that there are still some outside the main battlefield or the boundaries of the state historic site that could be potentially important locations and should be investigated.

“Within the park itself, we have learned that there are still artifacts. We suspected that there was a high likelihood that undocumented collecting had done away with most of the artifacts but we have found hundreds of artifacts. There are some specific interpretations that we’re still not discussing because they haven’t been published.”

Mangum said the battlefield site has been impact by construction through the years and just the maintenance of park has potentially impacted the site.

“If you’re talking about the battlefield, we know that people have for decades gone out there at night, or maybe during the day when nobody is around and done undocumented collecting,” he said. “They have stolen artifacts from the people of the state.”

Mangum said they have excavated the site marked with stones and believed to be the Mexican soldiers’ campsite and they lean toward the interpretation that it is not correct.

“We don’t know that for certain,” he said. “We are just not finding the artifacts that we would expect to find within the camp itself. You would expect to find more personal items, more broken dropped camping items, but we’re not finding that, just a smattering of dropped items of a personal nature, and some combat-type artifacts.”

Mangum said the Mexicans camped at the location for two days and “a group of men that size would leave a lot of stuff behind, especially if that camp got overrun.

“You had people who had camped there running through the camp and then the people chasing them running through the camp and you would expect to find a lot of items that would have gotten trampled into the ground and never got found again.”

He said they are not finding camp goods and camp items as they have in other short-term camps.

Mangum said the Texans camped on the west of the battleground along the shore of Buffalo Bayou.

“We have looked there a little bit, but not very extensively,” he said.