There are 22 channels available for use with GMRS, and 8 available for repeaters. All non-repeater channels are shared with FRS, but there are channel specific rules dictating wattage and the type of equipment available.
GMRS Repeater List
FR RPT = Fort Ross Repeater
MZ RPT = Muniz Repeater
TC RPT = Timber Cove Repeater
WW RPT = Wildwood Repeater
MH RPT = Mohrhardt Repeater
TV RPT = Teravana Repeater
OL RPT = Outlook Repeater
ST RPT = Siri Tower Repeater
MJ MPT = Mt Jackson Repeater
More Frequency information to come