Bring something to ward off porcupines (can‘t speak for the marmots). Spent the night in the overnight parking lot and (4 times) had to chase off a porcupine (who was gnawing on my car)...and it would not scare off easily. Rocking the car, loud noises, lights, etc. didn‘t work. Had to nudge and prod the little guy with a stick several times before it would scamper off...only to return as soon as I dozed off again. Crawled up into my engine twice, also.
Last year, I wrapped my car in chicken wire. That did the trick and wasn‘t hard to do, even by myself. The people next to me were up all night chasing off a persistent porcupine, while I slept like a baby.
BobbyFinn and KatieFinn brought granulated coyote urine. Worked for them and they have never had any issues.