Well, while the facts are carelessly mixed and muddled in the Professional Journalist's article, Camp Mabry is not just an Army post, it's HQ for several divisions of the National Guard, including being the Headquarters of the Texas Air National Guard. From The Handbook of Texas Online:
The state adjutant general's office was moved to Camp Mabry in 1954, and the Texas National Guard State Officer Candidate School was established there in 1959. A historical marker acknowledging the contribution of Camp Mabry was dedicated in December 1972....
...The Texas National Guard Academy opened at Camp Mabry in June 1984. Also located on the post are the headquarters of the Texas Air National Guard, the Texas State Guard, the United States Property and Fiscal Office, the Texas National Guard Armory Board, the Headquarters Armory of the Forty-ninth Armored Division, a clinic, a parachute packing and storage facility, and numerous supply and warehouse facilities.
When you drive past Mabry on MoPac Expressway, the most noticeable features are two airplanes and a couple of helicopters on display. (They even string lights on them at Christmas time.) Here's a picture I found online of one of the planes here, note the Texas flag and TANG emblems on the tail:
I don't know about the assertion that Bush was actually stationed at Mabry (I suspect the reporter is melding/blurring his facts a bit and means Ellington, but I haven't followed this closely enough to say Bush was never at Mabry), but Mabry is indeed TANG HQ, and Burkett could theoretically have seen some sort of records when he was there in 1998 (not saying I believe him, just that Burkett apparently was indeed working at TANG HQ in '98 when Bush was the Governor). I think that's why he is given so much credibilty, there are so many people that see him as the link, he just must have seen something because he was there, etc., etc. It's his claim to fame in Dem circles, apparently. Were I a reporter using him as a source, I would have certainly given a heckuva lot more weight to the disbelief and denials of Killian's family than CBS did.
In any case, Mr. Rigler went on to say that interviews with former National Guardsmen were leading him to believe the truth of the documents, if not their authenticity.
"It was so well known for years at Camp Mabry about Bush and his failure to serve in the Texas Air National Guard," he said, referring to the repository where Texas Air National Guard files are stored. "It was just so very, very common. You know, he didnt even show up out there during his whole eight-year tenure as governor and commander in chief of the Texas Air National Guardnot once did he go to Camp Mabry. So most people just sort of looked at him as a draft dodger. They didnt hold him in very high regard at all."
He continued: "The storyand Im talking to some people at Camp Mabrythe story about the files, the non-service, the memos, stuff like that, had floated around for years. For that reason, it makes you think its likely true."
I understand that TANG HQ was there. The question is, were Air National Guard personnel records stored there? We know for a fact that the Dept. of the Air Force maintains a dedicated personnel records archive facility in Denver that has the records of all Air National Guard members from all the states. Would 25 year-old records be maintained in two places?
For operational reasons, especially in the 60s-70s time frame, The Army and the Air Force had different relationships with their National Guard counterparts with the Air Force keeping the Guard units much more integral to it's operations than the Army. Air National Guard units, unlike Army Guard units, actually do preform active duty missions, outside of their state, or even overseas, directly under Air Force Command, on a daily basis. Army NG only do that when nationalized by presidential decree.