According to the local paper [1], from the top of Mount Diablo (east of SF Bay) it is possible to see Mount Lassen (approx 260 km away). "Although you can’t see Mount Shasta directly, you might be able to see part of the peak, refracted by the atmosphere." (That would be 380 km).

[1] http://www.mercurynews.com/2015/11/24/bay-area-facts-what-ca...