According to my files there are 3 control channels, 774.28125, 774.53125 and 774.78125.
They may have been doing firmware upgrades at the sites and moving the control channel around to make sure the upgrades worked properly. I have heard of reports of this at other sites as well.
If you have a radio capable of Pro96Comm each of the possible control channels are listed as either "c" or "a" for Control or Alternate Control ("d" indicates data, usually OTAR). Here is a snippet from a Pro96Comm file on Site 102 that was uploaded to the CARMA site a couple days ago. The data is from Friday:
-Frequencies
#Format: Channel,Usage,Frequency,Input Frequency,Hit Count
"01-1934","vdi",774.09375,804.09375,2
"01-1974","c",774.34375,804.34375,0
"01-2014","avd",774.59375,804.59375,1
"01-2054","avd",774.84375,804.84375,18
"01-2094","vd",775.09375,805.09375,18
"01-2134","vd",775.34375,805.34375,0
"01-2174","vd",775.59375,805.59375,16
"01-2214","vd",775.84375,805.84375,3