AggiePhil ... I could not link up with much info on Bryan Field. I know it opened in 1943 and served as a pilot training base, apparently at one time or other primary, basic and advanced instrument training. This is a look at the airfield layout:
Although the Air Force let A&M use the field from 1947 to 1952, it apparently retained ownership until it deactivated in 1961 and transferred title in 1963. Jerry O'Malley, commander of Tactical Air Command until 1985 got his pilot wings at Bryan in 1954. I had a flight physical there in 1955 and took a flight in a T-28 that year with Col John Way, PAS&T at A&M. (Gus Grissom served some time there as an instructor.)
TEEX occupies most of the developed areas of the base now with training for linemen, communications people, law enforcement and now Homeland Security. For several year Texas Transportation Institute has used the runways for vehicle crash testing, roadsign and barrier design and testing. Nautical Archeology at one time used one of the buildings for ancient ship preservation and study. The Ocean Drilling Program stores some of its stuff there.
In the part of the airfield where you see a network of streets, that area in the 40s and 50s was covered with frame barracks, dining halls and administrative buildings. When an air base deactivated those buildings were sold as surplus ... to colleges primarily for $1.
A&M bought a bunch of them, and I assumed many or most came from Bryan Air Base. About 25 of the two-story barracks were set up for married student housing in the area now occupied by foreign married student housing. Sixteen of the two-story barracks were set up on campus as classrooms ... between University Drive and the Reed-McDonald building.
With all the various activity taking place at the field now, I would hope someone has painted great big Xs at the end of anything that looks like a runway. (That big tower you mentioned is one of the activities that concerns me.)