California has two of these. Colorado, Tennessee, and Utah each have one. No other functioning exemplars of this exist in the United States. By way of comparison, Canada has three, all of which are in British Columbia.
Globally, the nation with the most of these appears to be either Iran or Switzerland; Switzerland has twelve and I think Iran has the same number, but I cannot determine that with precision. Italy is the runner-up with ten and Bulgaria takes third place with seven.