There's quite a few licensees on
464.100. Many of them are probably used simplex, but if you were close, to the user, you'd hear them. As noted, a number are hotels. DISD used to use this as their security channel (they now also have some officers who are certified as police officers). I've also heard some security/police ops on one of their other frequencies in the 'T' band. Not much that interests me, so I don't actively monitor them.
CareFlite is on a approx 300 ft tower, just southeast of Cedar Hill, and across the line into Ellis County. If you know where Ch. 11's tower is, look S/E. You'll see another tall tower (not sure, exactly, whose that is, but may be for one or more digital TV stations). You'll see another one past that one. That's
CERN. The main antenna 'farm' at Cedar Hill may be in your signal path to that tower, and attenuating the transmissions.