The City Dionysia in Colorado Springs.
It was the City Dionysia festival, complete with a performance of Euripides' The Bacchae.
There is, of course, a Facebook page, where you can see some photos.
I missed it by going camping, an homage to a different god. Maybe next year.
You have to admit that this event nicely counters the usual "Fort God" image that is commonly encountered.