Re: Colorado elk hunt, non resident, public ground.
Lots of good advice here so far, I'll throw in my 2 cents. I have three rifles that I have hunted elk with and do not hesitake taking any of them. For the most part I have used Accubonds recently and usually my .300 Win Mag with 180's. Has dropped elk in their tracks, that last two at 297 yards and 350 yards. I have also used my 30-06 and a 7RM. Scopes have been 4X12X40 Leupold, X9X40 Leupold and 4.5X14X40 Nikon. These last two elk have been the farthest shots I have had to make. I have shot 6 other elk all between 75 and 150 yards. They are big animals and I shouldn't have to say, you need to hit where it hurts. Get you some good optics, binos and maybe a spotting scope, I suggest that you use them more than you may think. And as mentioned, get in the best shape you can.
So all this isn't much new to add to the topic, but something I do have some more avice on is altitude sickness. I used to get it pretty bad. I now start taking Ginkgo Biloba (you can find it anywhere that sells vitamins) a couple months before hunting season. I used to get sick every trip for the first day, headache, vomit, would be fine after a day or so. One trip to Utah's high country I got incredibly sick, took hours to get back to the truck, never thought a man could throw up or at least try too so much. Ten years ago I heard about taking the Ginkgo Biloba and gave it a try, haven't had any problem what so ever since. So at least for me, it works and I still use it every year starting in July.
Have a good time on your trip, but elk hunting can be addictive. I've had the bug since taking my first elk (a 6X8 tule elk here in California in '96). I may even be in that same unit in Colorado, its a toss up right now between an OTC rifle permit there or a general archery elk tag in Utah, all depend on what we draw in the regular draws.
Regardless, good luck to all and may the tag Gods be nice to you.