The Sonora-Sinaloa Archaeological Survey (1937-1940) was conceived, designed and directed by George Valiant and lead by Gordon F. Ekholm. The project sought to fill the archaeological gap between the American Southwest and the northern Mesoamerican frontier covering the area from the international border to the Río Culiacan. Ekholm, accompanied by his wife Marguerite Wander, departed for Mexico in the fall of 1937. Over the course of three field seasons of six months each between 1937 and 1940, the project surveyed more than 175 sites between the Mexican states of Sonora and northern Sinaloa.