JFT has a stop in Kirkwood California. Register early, because it fills up super fast. There is also the Tahoe Jr Big Mt Series, which has events at Sugar Bowl, Squaw, and Alpine Meadows. Check out all of these, they're super rad, and there are tons of really sick kids competing. And throwing down some rad tricks off natural features.
If you're over 17, there is the Twisted Sisters Freeride comp at Kirkwood, and there is the Ralhves Bonzai Tour. All are open events, but fun to compete in and watch. Cheers