El Tesoro is produced at the La Alteña distillery in the highland town of Arandas. La Alteña was founded in 1937 and in many ways has shaped the progression to premium Tequilas as they exist today. El Tesoro(once, El Tesoro de Don Felipe in honor of Don Felipe Camarena who grew agave and made Tequila in the Los Altos region since the early 1800’s) is a quintessential highland Tequila made using traditional methods, with expert Tequilero and Master Carlos Camarena at the helm. The Tequilas are made using tahona crushed agave, fermented with fibers in wooden tanks, and uniquely distilled to proof, instead of diluting after distillation. Water used in the process comes from a deep underground spring on the property.