Is this for you or kids?: If for kids I would talk to your local 4H club and see when their next competitions. Many of their competitions are local, regional but at times they do CMP and postal matches or do matches for USA Shooting. I would start with this website for more information.Is there any organization in San Antonio doing CMP competitions?
I tried to do a bit of research, but the CMP page lists only JROTC programs and one gun club where you have to be referred by a member to even submit an app.
They do but all I could find were ROTC, JROTC and 4H programs in the San Antonio area.CMP website should have a list of affiliate clubs and locations.