i have heard of a vermilion flycatcher sighted in Fremont, CA. as i am not connected to any kind of rarity alert system, i do not know if it is still there. can anyone tell me if it has been sighted later than Dec. 7?
Looking at Sibley...they appear to Winter along the coast in most of California and are resident in Southern central California. E-bird might give you the information that you need, and or a US birder.
eBird is a good bet for finding individual sightings. I don't think you have to sign up to explore their data. Birdingonthe.net archives many state and regional birding listservs into a simple viewable webpage; a quick search indicates that there are several California lists so you'll have to pick the one for the area you desire.