We have stayed at most of the lodges on our annual week long fishing trip to the June Lake Loop. We have found that the Big Rock Resort is currently the best. The place is neat and clean and a good value for the money. We normal rent 3 cabins for the trip with 15 guys I regularly hunt and fish with. One bonus is each cabin gets a free boat daily. Also the west side has some great spots east of Fresno.
Here's a hatch chart, i stole from on line. https://mammothfishing.com/hatch-fish-charts-in-the-mammoth-lakes-area/
Stone fly nymphs and as far as terrestrials go, carpenter ants are most common/reliable in the areas i've been to but those on the west side of the crest.
There's a few other charts on line, I searched under ____ "hatch charts" or "fly fishing hatch charts"
Hope you go and have a great time!