Replying to Best places to hit in the summer

I'm Planning a trip through Montana,Idaho, Washington, Oregon, and Northern California Ill be traveling around June 16th next yer.The farthest south I am going in California is San Francisco. I know common places Like Mount Hood, Bear mountain,Squaw,and Boreal what are some other places to go that have some kick ass parks. I was just looking for some knowledge about some resorts that are still open during early summer because I'm from the Midwest and we have to stop skiing in early April. Thanks for the help guys.