Mission Puerto de Purísima Concepción was founded near what is now Yuma, Arizona, United States, on the California side of the Colorado River, in October 1780, by Father Francisco Garcés. The settlement was not part of the California mission chain but was administered as a part of the Spanish missions in Arizona. The Mission site and nearby pueblo were inadequately supported, and Spanish colonists seized the best lands, destroyed the Indians' crops, and generally ignored the rights of the local natives. In retaliation the Quechan (Yuma) Indians and their allies attacked and destroyed the installation and the neighboring Mission San Pedro y San Pablo de Bicuñer over the three days from July 17 to 19, 1781.