Dear shedhead
I will offer WATT I have learned in Radios but TUNE'ed to your specific question with a remedy, maybe.
First I would suggest searching the Internet to learn how various radio's and radio waves work and don't work.
All Cell Phones are actually just Radio's.
The best thing (my opinion) any Hunter can do is go onto ebay and buy used Police/Fire Motorola Radio's. Seek the highest WATT's available and recharging banks. Take time doing ALL research and possibly there is a Local Radio Business that rents Radio's out for Conventions, Football Games, etc... A Business that does such rentals will have their own Channel(s). Check to see if their channel(s) are used by Forrest Service, Fish & Game or anyone in the location you will be going to.
The ebay route can, at times, do the same job and you will own the Radio's, Batteries and Charging Banks. There are also businesses that sell new Radios and will have a person who can explain each model's capabilities. Just know ahead of time that when you use the word "Canyon" the sales agent will be worried. It will be understandable after the above "First" item is heavily explored.
Other's here may have better advice. I hope this get's you rolling.
Jagerdad