I’ve had a whole lot of fun camping near high somewhat isolated lakes containing nothing but Brooke trout at 9k’ to 10k’. An un-named little lake a 1/2 mile or more off the trail to more prominent lake or lakes seems to have good odds of light use. The last such lake we fished in mid July pre Covid produced over 100 little catch and release fish a day throwing nothing but foam hoppers near the shore.
Unfortunately the Covid mass vacation had 100 cars at trailheads that normally have 10, and much of the back country fisheries that aren’t stocked have had a giant reduction in numbers, which are slow to recover.
At least as far back as the Great Depression, many back country lakes were stocked with fish and fresh water shrimp - even in the lakes where the introduced fish didn’t survive, a resident population of shrimp is a good sign for large numbers of brookies. Some lakes in Idaho looked ideal, with large numbers of brookies in the streams below, but almost none in the lake for some reason. Same with some very nice rivers that should be full of fish, but aren’t and I’m not sure why.
Sounds like a fun trip - let us know how it turns out!