Weight and space are the biggest considerations when going on back pack fishing trips. For the occasion, there are lightweight tents, lightweight sleeping bags, freeze dried meals, and such. Packing fishing gear follows the same idea. Most high elevation lakes are the domain of trout of varying species, which are generally opportunistic and will eat whatever is available to them, so I keep my lure and fly choices on the sparse side.
The pack rod is out of its case, strapped to the outside of the backpack to reduce weight and space
I will pack a half dozen trout sized spoons, another half dozen small spinners, some small snaps, maybe a dozen no-lead split shots for weights, and few small dime sized or nickel sized bobbers, plus a few dozen flies. My flies will be made up of bead head nymphs, such as the prince, the pheasant tail, and the zug, plus a few bigger, bushier flies, like a double shrimp, some buggers, and a few spratleys. In all, it’s a little tackle box that could fit in a jacket pocket, but will catch trout most of the time.
Make time for a trip into the backcountry and the rewards are plenty
As for a rod, I say make it easy on yourself and buy one of those four piece light weight pack rods. They are terrific. The four piece Fenwick Eagle 7 foot, medium-light trout rod has been my "go to" pack rod for years. After the rod, get a lightweight, packable reel spooled with quality 4 lb line and you’re set. You’ll be able to make long casts and reach many of the trout.
A quality pack rod makes is much easier to cast to and catch trout
Get your hiking boots on and go find the adventure
There’s something special about being at a backcountry lake, catching trout, and having the time of your life. I suspect that once you do it and have one cool experience, you’ll be quickly looking to other lakes and other adventures, because catching fish in the company of mountains is a lot of fun.