Shasta. Fire up your quads, start at 4am, something like 5k vertical up and down. A classic summer descent.
Pickings are going to be slim this year in California from what I have seen. If the snow come late (and often it does) there might be several resorts still open in June. Look at Mammoth, and Tahoe areas to see what they are doing. Mammoth is often open in June so that is probably your best bet in Cali.
I'm not sure spirit chief Skell would like people snowboarding on his mountain.
Thanks for the sites' references.
Now I just have to keep my fingers crossed...