There is no black powder for sale in Bexar County, I'm afraid to say. Don's Gun Shop off 410 on Fredericksburg Road closed. That was the very last brick and mortar shop to get it. Powder Horn--a wonderful gun store!--stocks propellants for modern center fire reloading, and possibly alternates to black powder, but not black powder. Nagel's does not stock black powder. Rumors that Bass Pro has it have proved unfounded.
Anyone who needs black powder in the cradle of the Texas Revolution and site of the Alamo has to buy it online from an outfit in Arkansas or from Idaho. A disagreeable state of affairs. People who've gone to Brady and elsewhere for state-level muzzle loading shoots and meet ups and rendezvous report low attendance, and few sutlers or trailers of folks selling powder where before there were many. A sad state of affairs!
I'm using powder I got from Winchester, VA from a fellow muzzle loader in the N-SSA who agreed to get me some!