Hey NS!
I've been working on this website for a little while now. Its a website for saving skate spots, but there are categories for pretty much every action sport, including skiing obviously. You can mark your spots as private. There are many features on the way, and I can be pretty reactive to requests. I'd love to hear any feedback you might have.
http://shreddymaps.com
For example, SLC Rail Gardens:
http://shreddymaps.com/#/spots/9407