Oshara Tradition, the northern tradition of the earlier Picosa culture, was a Southwestern Archaic tradition centered in the area now called New Mexico and Colorado. Cynthia Irwin-Williams developed the sequence of Archaic culture for Oshara during her work in the Arroyo Cuervo area of northwestern New Mexico. Irwin contends that the Ancestral Puebloans developed, at least in part, from the Oshara.
The Picosa culture encapsulates the Archaic lifestyles of people from three locations with interconnected artifacts and lifestyles. It was named by Cynthia Irwin-Williams in the 1960s for those areas: Pinto Basin (PI), Cochise tradition (CO) and San Pedro (SA), which all together is "Picosa".
The people in the dispersed locations in the American Southwest lived in similar housing, used similar burial practices and had similar lifestyles. The artifacts from the sites demonstrate similarity in the technology used and personal material goods. The Picosa culture has been found in the states of California, Arizona, Utah, New Mexico and Colorado. It was the predecessor to the Oshara tradition.