Poked around the NIFC and found this:
Interagency Standards for Fire & Aviation Operations 2009
Chapter 15 has some frequencies:
168.625 National Air Guard
168.650 National Flight Following
166.675 National Interagency Air Tactics
167.950 National Interagency Air Tactics
169.150 National Interagency Air Tactics
169.200 National Interagency Air Tactics
170.000 National Interagency Air Tactics
123.975 National Interagency Airtanker Initial Call
163.100 National Government All-Call Frequencies
168.350 National Government All-Call Frequencies