I just received a report of confirmed use of the MOTOTRBO digital mode on 409.7375 MHz, somewhere in the Southern California (LA) area. MOTOTRBO is a propriatory digital radio product sold by Motorola, and appears to be gaining favor with hospitals, casinos and possibly some non-law enforcement federal opertions.
I have not copied any TRBO traffic on that frequency in my past SoCal visits, but have heard what I suspect to be TRBO digital on 407.3375 MHz and 413.5250 MHz, which I highly suspect to be coming from the VA Medical facility along I-5 north of San Diego.
Back in May, while in Las Vegas I heard many transmissions on 406.9375 MHz that sounded a lot like the known MOTOTRBO users in my home area. I've heard several other federal users, including 406.6625 MHz, the Federal Reserve Branch in Chicago, 407.9375 MHz coming from somewhere in the Seattle/Tacoma area, and 409.4375 MHz confirmed as coming from the VA Medical Center in Vancouver, Washington.