Do you know if these are P-25 or conventional?
State agencies and local fire departments are not gearing up to use digital on VHF and until, or if, they do, don't expect to see the feds using P25 on wildland mutual aid frequencies. I don't think digital is safe on wildland fires due to the all or nothing characteristic of digital. That is, background noise is not an issue on digital systems, but "going digital" is. The latter refers to the weird, Donald Duck speaking into a can sound that occurs in the foothill areas of some large cities. Up to a point signals with a lot of background noise can be copied, but it doesn't take much to make a digital signal unintelligible.
As these frequencies get used, reassignments are possible, as interference will be experienced between simultaneous incidents. I think some tweaking is possible, although the people assigning these frequencies are fairly experienced with the terrain and distances needed to minimize interference. Use of CTCSS could reduce weak interference, however, its use on wildland mutual aid, simplex, tactical frequencies is without precedence.
This is but another development of getting rid of single frequencies used for one function nationwide. Air to ground is no longer one frequency in California. Now there are two air to air FM tactical frequencies for each forest in California and possibly for each interagency communications center in other states. There are two, and sometimes three, air to ground frequencies for every for almost every 105 interagency communications center in the country, the exceptions being in the midwest and east. There is a national flight following frequency and some communications centers have a local one as well. Most units, be they parks, forests, BLM districts, wildlife refuges and Indian reservations have multiple nets with repeaters covering most of their jurisdictions. These have names such as forest, district, park, refuge, reservation, fire, admin, command, law enforcement, service, medical, and SAR. If you are interested in a longer term perspective of how things were before this type of development, the latter portion of this post recalls what frequencies used to be available for land management and fire fighting. If you are not stop reading here.
OPTIONAL INFORMATION BELOW
When I started with the U.S. Forest Service in 1974 "air net" had not been around all that long. Its frequency was 168.625, which is now "air guard." Air net was used for air dispatch, flight following, air to ground, air tactics and even, in many locations where National Forest dispatch offices were close enough to do so, an inter forest dispatcher's intercom. In my early years I was in the field nearly every hour that snow wasn't on the ground and would be out there when fires were active, but on occasion would be in dispatch getting information for fire reports, keeping company with, or harassing, the dispatchers because they spent all their time alone in a little room. I would hear things such as "Tonto, Coconino, the large one Promontory (lookout) has at 282 (degrees) is the same as Apache Maid's (lookout) 167 (degrees). The fire boss is only asking for one slurry bomber (terms have changed) so send yours to the A Bar S (Apache-Sitgreaves) east of Chevlon Butte, I just got off the phone with Springerville and that one is moving out on them." Note that this is all aircraft related traffic and that a zone coordinator role is not evident. I would also hear more routine traffic on "air net" such as "Coconino, Kaibab, one of our FPT's (fire prevention techs) found an abandoned campfire on your end of Lily Pond Canyon and you need to send one of your FPT's to put it out." Heaven forbid a Kaibab patrol work 200 feet on the Coconino's side of the boundary!
Lookouts near the boundary of two forests would have a packset for each forest on their tables. If phones and the air net were tied up dispatchers would call these lookouts to ask what the situation was on the other forest. Lookouts that became very busy with lots of traffic from each forest were staffed with married couples so each could work one forest during lightning busts. They would not only be reporting locations and conditions of fires, but relaying all traffic from some of those. I believe each forest now has a repeater there. Promontory Lookout is on the Apache-Sitgreaves National Forest in Arizona and is very close to the boundary of the Tonto and Coconino National Forests, with the common point of all three forest nearby. A radio for each forest is located there. Its location is on the edge of the Mogollon Rim, a prominent WNW to SSE feature with a significant elevation change that runs over half the width of Arizona. During the monsoon season of July-mid September the rim gets some of the most intense lightning activity in the world and most intense lightning activity over forested lands in the country. Promontory Lookout can be insane during the monsoon season and two people may not be sufficient, one person per forest radio is needed. You can visit Promontory, it is just off the highway from Payson to Springerville, but the public is kicked out during fires. I've parked below it and fired up the scanner during intense lightning storms, WOW!
Interagency wasn't even a word then. If we saw a fire in the distance that wasn't on our forest or off National Forest land we would not even call it in. "That's their fire and we kill our own snakes, not someone else's. Lookouts would call in everything they saw but the dispatcher could not locate most of them because they weren't on the their forest maps nor any of the other forest maps kept in a drawer near their consoles. So the dispatcher would get on the phone and might eventually track down the jurisdiction of the fire. If the fire was on BLM managed land is was considered in "never-never land" as the BLM wasn't much of an agency, let alone have fire fighting capability. BLM land was in sorry shape as the Congress didn't have a common set of policies and laws as to what was going to be done with it, the only policy present was to get rid of most of it and there were very few takers at the time. [A compliment is due here, the BLM finally received clear direction, policy and law from the Congress in 1976 and they have improved hugely!] None of the federal agencies had similar job qualifications or command systems so a fire with multiple agencies on it didn't occur very often. There might be local agreements for mutual aid, such as that between Grand Canyon National Park and the Kaibab National Forest, but agencies usually filled their needs from within. However, red cards (fire qualification) were actually red!
Some of the more remote and large forests in Idaho, Montana and Wyoming as well as forests in Utah, Nevada and Colorado didn't have forest dispatchers, they had ranger district dispatchers. The radio systems had a ranges capable of covering one district. Networking the entire forest together wasn't being done there yet as that would have required remote bases connected by VHF or the very new UHF frequency band. The technology to do so was 15 years old at that time but funding did not keep up with technology. We didn't have repeaters, we called the nearest lookout to relay traffic to other mobile units and, in many cases, to the dispatcher as the location we were in might be blind to the dispatcher's radio, which was usually a remote base on a mountain next to town linked via phone lines. In the fall, winter and spring when a lookout was not staffed we weren't able to talk with anyone from these blind spots.
Some of the older employees I spoke with had been using low band radios about 10-15 years prior to my starting and some retired employees would recall the days of throwing a long, random wire antenna over a tree limb and use the VFO to tune a frequency for calling the ranger district office.
The aircraft only had an air net radio as radios with a sufficient capacity to cover every forest were not available or the number of crystals needed could not be afforded. The only ground unit that carried the ranger district's one air net packset (not handheld it was in a small pack) was that of the FCO (fire control officer - we didn't manage em, we put em out!). If the FCO was sent on a fire off forest or on another fire on the forest then the dispatcher would relay the traffic between the slurry bomber (air tanker) and ground units. Sometimes the pilot would be on the wrong fire and the instructions relayed did not make any sense so he would just dump the load on the wrong fire. Wulfsberg sounded like a place WWII criminals were put on trial and not a radio capable of tuning every frequency in a band. For those of you who don't know, Wulfsberg radios were capable of having each digit (six at the time) dialed in to enter a frequency. The first Wulfsbergs did not have the capability of receiving one frequency and transmitting on another, or transmitting a tone so repeater use was not possible. Some of the aircraft in California had a UHF Wulfsberg as well so they could talk with police departments at first, and then later, fire departments that had moved up onto UHF.
In those days California already had zone coordinators (North Zone and South Zone), which were the only two in the nation that performed as coordinators between multiple jurisdictions and agencies. Each Forest Service region, Park Service region and BLM state office had a coordinator that would, in turn, work with the Boise Interagency Fire Center (BIFC). North an South Zones each had a "zone net" allowing dispatchers to speak to each other via a dedicated point to point radio network. The only separate tactical frequency was the Forest Service's Region 5 "Crew Net" on 168.2000. As for the zone nets, they have been dismantled and have been piggybacked onto the state's microwave system. They also use ROSS (Resource Ordering and Status System) for ordering resources from each other other now. Its been 20+ years since I could hear forests such as the Angeles call the San Bernardino to make requests for things like rolling their Mormon Rock engine to the east end of the Angeles Crest Highway, while in my house in Mono County.
Thankfully we don't have to buy crystals for every frequency anymore and decide what we aren't going to listen to if we put a new one in. If a big fire hit some of us owned crystals for frequencies used on large incidents only. We had to take the covers off radios, use needle nose pliers and replace crystals to listen to the action on a fire that escaped initial attack. We had to find out the frequencies from people inside agencies that talked to their radio techs. In that way our scanners are now simple, but programming them is more complex and time consuming than it used to be. Thank goodness we have this website to communicate with each other!