My buddy and I did the ride from CM -> Mae Sa Riang -> Mae Hong Son -> Pai....at the end of March, and the first 2 days in and around Mae SaRiang had a bunch of small fires burning around making a TON of pollution. And on the way out of there, I went through a few small canyon type valleys where entire sides of hills had been burned out. Maybe if the government at least had a free crop-tilling service they could let people use instead of just slow-burning their fields like we saw them do, it would make a dent in all the smoke. It was gross in a few places driving through it.