We took our time cruising over The Hogsback and down past Calf Creek taking in the now-familiar views one last time. Over the Escalante River and past the Kiva Koffeehouse until we hit the long, straight stretch that leads to Escalante. As our speed increased, we noticed that the Jeep had developed a pronounced vibration. Playing with the accelerator, I decided it was coming from a wheel which seemed out of balance. I suspected maybe we’d thrown a wheel weight so I stopped once again at the minimart with the air pump as we entered Escalante. This was getting to be an annoying routine. The tire pressures were all fine and there was no evidence that a wheel weight was missing. On closer inspection I saw that there was a blob of mud on the inside of the left rear rim. We must have picked it up back on the Notom Rd. going through the low muddy sections. The mud had dried there and had gone unnoticed since, until now, we’d been going slowly on bumpy roads.