There is also camping allowed at the trailhead. There's not really a campground, but people spend the night before hitting the trail in the morning. I've done it twice. I've never had a problem with marmots there, but I know employees at the research station take steps to prevent damage. If you are only there for 1 day or night, I would not worry about it.
It is an excellent warm up hike, or just camping at the trailhead is good to prepare for Whitney.
