ABSTRACT
The pascola is a masked, costumed performer whose presence is necessary at all Yaqui and Mayo Indian fiestas. Pascola costumes are described in their regional variations, with special emphasis on the masks. These latter fall into three separate but related styles: Yaqui, reaching from central Arizona south to the Rio Yaqui in Sonora; Rio Mayo, including southern Sonora and a few villages in northern Sinaloa; and Sinaloa, encompassing the upriver villages on the Rio Fuerte and stretching south to the Rio Ocoroni. Changes in mask style over time are described for each area. Mention is made of the curio trade and its influence on mask making.