Here is a list of Yellowstone National Park freqs courtesy of Peter Sz
North District
166.3750/166.9750 Henderson repeater (192.8 Hz pl tone) (Lamar District)
166.3250/166.9350 Washburn repeater (167.9 Hz pl tone)
166.3750 Lamar direct (simplex)(192.8 Hz pl tone) (Lamar District)
166.3250 Washburn direct (simplex) (167.9 Hz pl tone)
South District
165.5875/164.8000 Sheridan repeater (110.9 Hz pl tone)
165.5875/164.8000 Top Notch repeater (118.8 Hz pl tone)
165.5875/164.8000 Bechler repeater (127.3 Hz pl tone)
165.5875 South Direct (simplex) (110.9 Hz pl tone)
West District
166.8750/169.4000 West repeater (136.5 Hz pl tone)
166.8750/169.4000 Holmes repeater (146.2 Hz pl tone)
166.8500 West Direct (simplex) (136.5 Hz pl tone)
Parkwide Freqs
167.1500/163.1250 SOA (Portable) repeaters (SOA 1 206.5 Hz pl tone, SOA 2 218.1 Hz pl tone, SOA 3 229.1 Hz pl tone)
168.6125 NPS Common (136.5 Hz pl tone)
172.5000 Fire Cache (wildfire) (103.5 Hz pl tone)
163.100 Usage unknown, maybe MTNCE
168.350 Usage unknown, maybe MTNCE