KHJK has two licensed auxiliary sites, one of which is 100kw on the same tower as the main but with a little lower height. The other one is located off Decker Drive adjacent to the Exxon-Mobil refinery in Baytown. It's licensed for just 12.5 kw with considerably less height, about 460 feet.
I'm thinking it's the Decker Drive site. I'm not hearing any IBOC sidebands (allowing reception of KBPA!) I don't think the aux site has IBOC. We also have the reports that the signal has disappeared in Beaumont.