During the great 3 May 1887 Sonoran earthquake (surface-rupture endto- end length: 101.8 km; M_W 7:5 ± 0:3), an array of three north–south-striking Basin and Range Province faults (from north to south: Pitáycachi, Teras, and Otates) slipped along the western margin of the Sierra Madre Occidental Plateau of northern Mexico. This detailed field survey of the previously undocumented 1887 earthquake rupture zone along the Otates fault includes mapping the rupture scarp and measurements of surface deformation at 25 sites.