Only gartersnakes. They hardly count. I know what you mean though Dr. So many visitors who grew up in the tropics do ask me that question. Specifically, Tree Snakes. I guess those are widespread.
But here? Nothing but mouse eating snakes. Not a single species of tree snakes in California...Rattlesnakes in hot areas of California. Again,in the urban bay area proper? Not warm enough. Well,I've seen shed skins of rattlers in the hills. Even then,they were young ones.