A Mazatlán operation run by Johann and Sandra, licensed and insured and accredited by both ASTA and IATA, with bilingual guides.
They cover the old town and the malecán, the colonial mining villages of Copala and Concordia up in the sierra, tequila-town day trips and cruise-ship excursions.
Unusually, they publish only North American numbers — a toll-free line and a WhatsApp number on the same range — and no Mexican one. Email works.