There's nothing better than waking up slopeside
A subject near and dear to my heart. We spent last winter in a twenty-four foot camper in the West. We only spent one or two days at each place so no long term advice here. I would stick to the Northwest if you're going to live out of your camper for the season. Here are some of the tips we picked up...
100daysofwinter.com
California:
North Lake Tahoe: We stayed mostly in the Safeway parking lot in Truckee and the the Cal-Neva Casino in Crystal Bay.
South Lake Tahoe: The Horizon Casino in Stateline has tons of room. Check with the front desk.
Mt. Shasta: There's a section in the way back corner of the parking lot.
Oregon:
Willamette: Has hookups and is open four days a week. Get there on a Wednesday night.
Mt. Bachelor: We stayed down in Bend and didn't get hassled at all even with parking on the streets.
Mt. Hood: You need to buy a permit (about $5) to spend the night anywhere around here. There's overnight spots at Timberline, Mt. Hood Meadows, and spots around G'ment Camp.
Washington:
Crystal: Has hookups. I believe there's a two week limit.
Summit at Snoqualmie: You can grab a night without hassle in the Snoqualmie casino parking lot.
Idaho/Montana:
Didn't have the camper during this stretch but all these ski areas tend to be absolutely awesome when it comes to parking lot camping.
Colorado:
Summit County: Breckenridge is terrible for campers and the beach at A-Basin is a shell of what it used to be back in the day. We did find one extremely tiny parking lot in Frisco that allows 24-hour parking -- including overnight for free.
Wolf Creek: Spent three nights in their lot during an epic storm. No problems.
Durango: Stayed downtown in residential neighborhoods.