Those buses carried 250 California teenagers on a ski trip, including teens from Clovis.
Investigators made the bust in Elko, Nevada. This was not a school-sponsored trip.
The teens were traveling from California to Utah for the ski trip.
A store clerk at a truck stop tipped off police after seeing passengers smoking in the parking lot.
"Some of them apparently were smoking or maybe even smoking marijuana outside the bus, and it appeared suspicious to the people at the Maverick. The Maverick store people called us," Elko Police Chief Don Zumwalt said.
The teens were let go because there's not enough jail space in Elko. Otherwise they would have all been charged with a misdemeanor.
No one on the busses claimed to be a chaperone.
The tour bus company said it is impossible to track what passengers bring on the bus.