Probably any of the '06 based calibers, 270, 280, 30, 338-06, 35 whelen, etc. will do the trick for elk. Heck a 30-30 has more then enough energy at the 100 yard range as long as you do your part. Your bigbore lever guns, like the 1895 marlins and 444 marlins are great elk medicine. There are a slew of magnums that work, 3 of which are in my cabinet. 7mm remington mag, 300 ultra mag, and the venerable 375 H&H, all of which are well suited for the task, maybe even a bit too much, but work fine as long as you can shoot them accurately. A light 30'06 scoped would be a great pack rifle as would a marlin guide gun, especially if you are going to be doing alot of travel on foot. I got the wife a new marlin XL7 in wood (30'06), nice and light with a recoil pad. It was fairly inexpensive, and from all the reports I have read, they tend to shoot as good as rifles costing twice as much and weigh more. Cant wait to take it out!