FE Warren Helos
The helos (UH-1's) from FE Warren can be heard on 271.9 uhf (am) and use the callsign "Blade xx"
Might also check out the Wyoming National Guard at the airport, 153rd Airlift Wing. They fly the C-130H-3 and are very active using callsign "Teton xx" their command post freq is 257.1 used to be called "Cowboy Ops" they also will use the callsign "MAFFS x" as they are one of several units that are used for airborne fire fighting.
MAFFS stands for "Modular Airborne Fire Fighting System" about 3,000 gallons of fire reterdant in 6 seconds or they can select how much to disperse on each drop and can make several drops.
The 302nd Airlift Wing (AF Reserve) from Colorado Springs (Peterson AFB) are also MAFFS aircraft, their normal callsign is "Summit xx" also flying the C-130H-3.
Freqs for the airport can be found here:
http://www.airnav.com/airport/KCYS
scroll down to the communications section.
Hope this helps out.
73, Rex