The idea of this scavenger hunt was better than the actual experience. The website wouldn't initially accept our code. We were helped by a friendly customer service rep and the issue resolved.
Shortly after figuring out the first clue, the "yellow line" disappeared into a museum courtyard that had closed for the day. It was around 4-5pm. And so ended our hunt.
Admittedly, we were late coming into Tucson and our family of four was a little road weary. Our usual curiosity and tenacity couldn't carry the day.
We thought about going back during our visit, but other plans carried us forward.
Overall, it's a great idea.