Here's my equipment observations:
Rope - you cannot have enough rope for lashing quarters, dragging them, or hanging them.
Your own large coffee cup and or thermos - beats the heck out of a plastic cup any day.
A small, foldable camp shovel- for any digging, especially a proper cat hole.
Ammo - you'd be surprised how may people show up with only a few rounds or none at all because they forgot...double check!
A real canteen or other water container, including the camel type holders with a tube - plastic bottles are weak and can break in your pocket/pack, a disaster in cold/freezing weather. You need to hump a lot of water!
Good flashlights, get the high intensity type, they blow away the regular mag lights. A small one and a more powerful large one.
A headlamp that'll securely attach to a brimmed hat - essential when you gut and haul. And extra batteries for the darn thing when you discover it's has somehow turned itself on in your pack!
Large tarps with grommets for dragging out quarters or making an emergency shelter.
A small flask for whatever spirit you prefer- nice to share if things get tough or you want to celebrate with friends when you get one.
A knife sharpener- elk hide will dull your knife blade fast, and I mean really fast!
Large, contractor grade plastic bags (40 gallon or larger), and large zip lock bags - you'll want the strong contractor grade bags to protect quarters or big cuts of meat, and the tough, big zip locks plastic bags for your back straps and tenderloins. The regular size smaller plastic bags at the grocery store are too weak, too small, and tear too easily in the field.
Pain reliever pills (Advil, etc.) and tums or other antacids- for sore muscles, headaches, and acid stomach you might have to deal with due to hard work, altitude, or a bit of bottle fever from celebrating your elk (ahem ahem, lol).
Some kind of urine receptacle that you can use in your tent at night - so that when you have to go, you don't have to unzip that tent and wake up your tent mates going in or out of the tent. And it sucks to leave a tent and go outside when it's 10 degrees with a blowing wind!
A butane heater with a large (at least 5 gallon?) propane tank - you'll burn through those small tanks way too fast, so bring lots of them. And a good lantern with extra mantles (sp?).
A good sleepin pad that will insulate your cot.
A sidearm revolver in .357 magnum caliber- for wearing in camp or in the field after you've tagged out (you can't carry a rifle in the field after you've tagged out) - for security purposes. There ain't no law deep in the mountains, and no 911 available, so you need to be able to protect yourself from potential bad 2-legged creeps. At least it would have made me feel more secure.
That's all I can think of right now.