NewsheepersDamn i can't get a campsite then? this is a bad idea then. I am serious about going but I can barely trust my car to make it to school rn.
you dont need a campsight. Most camping is FS or BLM land. Free. Id suggest snagging a month long onX membership so you're confident you're in the right spots.
Whats your car? It can be tough to get around on the east side of 395 to camp spots without an okay amount of clearance. Most of the ones on the scenic loop should be accessible in smaller cars though. At least in my experience.
Camping wont really be possible without a car though. Youre outside walking distance to the mountain for the most part. Unless you find someone to camp and drive you to the mountain it would be pretty tough. Hitchiking might work okay if you are on the scenic loop.
if you're able to make it to Reno, EST runs busses from reno to mammoth with a couple transfers.
https://www.estransit.com/routes-schedule/
I might head down once more this year from reno. But itd probably only be for a day so you'd be SOL once I dropped ya off.