and equipment needed to dress and drag out the carcass.
By yourself? THAT ain't happening - not on an elk.......As mentioned above - altitude sickness will kill you if not careful - you need to get there a few days before you hunt just to let your lungs get used to it. I lived in CO and NV - average ASL about 5000......going to 8 or 9 will make your lungs feel like they are going to burst,.
You'll need survival gear - flame source, food, water, emergency sleeping bag/tarp/space blanket....rope, spare gun parts - scope, bolt, ammunition, extra socks - (dressing in layers) goretex everything helps.....toilet paper - besides the obvious, helps with starting a fire - GPS, maybe a sat phone or similar if you're hunting alone
If oit hasn't been mentioned - moleskin and a water purifier (looks like a straw), and a firestarter brick with striker, a whet stone to resharpen your knife - (amazing how fast an elk can dull the best knife)
As mentioned, NO cotton - silk or alternative to wick moisture and wool
don't forget GOOD glass, and sight your rifle in AFTER you get to your elevation