since it is known that he had ties to Enid, Oklahoma, who is to say he couldn't show up in Oklahoma?
Since he was a Vance AFB pilot training student who never made it to becoming a pilot -- either quit or failed out somewhere in the process -- he could theoretically have an axe to grind with people who graded him poorly.
Strangely, that was one thing that he did not bring up in that manifesto. He seemed to cover every other aspect of life, though.