You have not said what you are going to use the pack for. There is a lot of difference between a pack for hunting elk and a pack for carrying out elk.
As one person mentioned I seldom have a heavy load bearing pack on while hunting. I dress the elk and then go to the truck and drop off the rifle and grab the load bearing pack.
How many trips and how much you carry depends upon your physical condition and whether you like to carry a few heavy loads or more loads but lighter. Just personal preference but a 9000 feet elevation the lack of oxygen is really tough.