The employees of Canyon Tours (and a few other rafting companies) patronize either the laundromat or the Burro and sometimes both... load the clothes into a washing machine, drop some quarters in it, press START, go have a beer and a burger, come back to the laundromat to move the clothes to a dryer, drop some quarters in it, press START, go have another beer...
Many jurisdictions have laws about underage patrons even physically being in a bar. Arizona in the SLT universe is different - underage customers are welcome in the Burro, but are limited to non-alcholic beverages.
From the books:
As always, they were late getting unloaded and getting gear maintenance done in Flagstaff, but this time everyone went over to the air-conditioned Burro, even Glenn, the teetotaler Mormon, who drank fruit juice while the rest of the crew had a few beers and Burroburgers, food they didn't have to cook for themselves.RR12
It was well after dark when they wrapped up; they headed over to the Burro, even the high school kids, who were drinking sodas RR24
Al takes Jon, Tanisha, Preach, Crystal and Nanci there... "If I might make a suggestion," Al said. "Preach, Nanci, I know you don't drink, but I think they still have 7-Up on tap down at the Burro. I think I'd be willing to buy us all a drink while Karin stays here and calls him"GT11
("him" is referring to her ex, Pete).