-THREE ways to start a fire (strike anywhere matches, flint & steel, cigarette lighter)
-MAP & COMPASS. A GPS is great but IMO it is no substitute for a USGS Quad map when trying to figure out where you are and where you think the elk may be.
-SIGNAL MIRROR & WHISTLE. To help the search party find you...just in case.
-BIVY BAG or EMERGENCY BLANKETS, ROPE or CORD. To set up a primitive shelter if the weather gets bad.
-WATER PURIFICATION. Never drink mountain water unless it is filtered. There are a lot of options but I prefer "Aquamira". It costs $15 and will last you weeks of constant use.
-TOILET PAPER! (self explanatory)

That stuff is mandatory just for SURVIVAL. As far as the Elk hunt itself, add the following:

-knife sharpener
-cloth game bags (roughly 6 for a decent sized bull elk)
-bone saw
-calls, scents, etc.

Lastly and very important: SUNGLASSES and BRIMMED CAP. I'm not sure which state you are hunting in, but here in Colorado your entire trip will be miserable without these two things.

And I'll add a good lip balm and sunscreen.
I had it and I'm REALLY glad I did.

Thanks for the input.

also if it is going to be warm a can of black pepper will keep them b-52 flys away from your meat. It don't take them long to find it, borrow and start laying eggs.