Prehistory is the study of humankind before events could be recorded in writing. In the American Southwest, prehistoric times ended in the mid-1500s when Coronado and his men explored the region. The Hakataya (the name is based on a Yuman word for the Colorado River) occupied what today is west-central Arizona, the northern part of Baja California, southeast California, and the southern tip of Nevada. The material culture of the Hakataya (also referred to as Patayan) varied regionally not only because of its adaptation to different environments but also because it borrowed cultural traits from several neighboring groups. Relatively few Hakataya sites have been excavated compared to the number of sites of the Mogollon, Hohokam, and early Puebloans. Even though on the map the late prehistoric cultures of the Southwest appear to be separated from one another by sharp boundaries, some overlapping did occur. The most outstanding example of such blending is the Sinagua culture of central Arizona.