It's a Colorado tradition to keep Christmas lights on display until the National Western Stock Show finishes at the end of January. But what do you do this coming January, since the Stock Show's been postponed until 2022? The short answer is, keep the lights up until January 24 in a show of support, says the Stock Show's Karen Woods. So how did the tradition start, and were outdoor Christmas lights really invented in Denver? We turn to a former historian for answers.