Replying to Best ski place for winter and mtb for summer?

im traveling next year to california for about 1 year in december and during the stay im having 6 month to travel around, so i wanted to ask if people here knows what is the best place to go ski in the winter and after the season ends to go for some mountainbiking in the same estate, hopefully a place with good downhill tracks, or more related to gravity mtb. with a few recommendations i could straighten my options so any support is totaly welcome