On the northbound leg I saw a cyclist pulling one of these, I haven't seen one before-
About four miles south of the Butler terminus, stopped at the Derailleur Bike Shop and Cafe. Pretty neat place. Fancy coffees and wonderful grill cheese with sun-dried tomatoes that would qualify as artisanal if this place were haughty, but it's not. I hope they do well.
Cafe in the front, bike shop in the back: it's the new trail mullet.