My radios have 3 of those programmed.
SPLX 4 866.9625
SPLX 5 867.2250
ALL LG 867.2750
There is another channel,
SMA 10
which gives a closecall hit on 822.7875 CTCSS 156.7 (at least I'm PRETTY sure that's the input, not an output...don't know for sure that it's not repeated)
Dunno what the use of the last one is. To my knowledge, none of my guys (for any legitimate purpose at least) have used the simplex freqs. They talk about the good-ole days with simplexes, but I don't think they know they have any, what to use them for, or how to access them on their radios. To be honest, I can't think of a whole lot of uses for them either, with how many talkgroups exist on the system...barring some major emergency or unforseen disaster.