Greetings from New Mexico, and I hope you have a great time and hunt. For hunting out west you don't need a 26 inch barrel, although it would add a little velocity. A 22 or 24in barrel is plenty sufficient. Either a 270 or 30-06 makes a great round, and both are the most popular rounds, along with a 7mm Rem mag out west. You don't need a magnum, and although the newer rounds have some theoretical long range advantages, from a practical standpoint aren't necessary. You will find a lot more ammo options (and cheaper) if you use a standard caliber. Practice as much as you can is a lot more important than barrel length or the latest rage caliber. I am 71 and still hunt regularly, and I can't begin to count the deer and elk I and my family have killed with a 270, 30-06, or 308. Good luck!