The long conflict between colonial Spain and the Comanche people reached a climax in 1779, when Juan Batista de Anza, governor of New Mexico and leader of the first overland trail to California, led a six-hundred-man army reinforced by several hundred Indian auxiliaries that killed the Comanche chief Cuerno Verde and about fifty warriors southeast of here at the foot of Greenhorn Mountain. Cuerno Verde stood as a leading figure of the Comanches, who dominated the southern Great Plains for most of the 1700s and kept Spain's New Mexican colonies under near-constant siege. The battle significantly changed the balance of power in present-day Colorado, and for the next seventy years Spain and then Mexico controlled all territory south of the Arkansas River. In the nineteenth century, many trading firms unofficially encouraged their agents to marry Native American or Hispanic women because such unions strengthened profitable cross-cultural trade relationships. These women supported the trappers and hide-hunters by hunting, trapping, skinning hides, tending herds, defending homesteads, raising children, preparing meals, and making clothes, and their skills and regional connections gave some, including Teresita Sandoval, enough power and independence to shape their own lives. Often overlooked in history textbooks, they were indispensable to the development of Colorado's first export industry.