Culturally, the Borjeño were like other Peninsular Yumans of relatively late prehistoric and historic periods in central Baja California. However, they lived in more widely scattered groups because of the greater scarcity of water in this part of the peninsula. Immediately to the north of them at Bahía de San Luis Gonzaga--at approximately the 30th parallel--a decided break with the Peninsular Yuman tradition occurred. In 1746, during a voyage up the gulf coast from Loreto to the mouth of the Colorado River, Father Fernando Consag noted that (1) the Spanish and their "Cochimí" interpreters could not converse with the natives; (2) the natives had dogs; and (3) the Indians had pottery vessels (Venegas, 1944, III:107-109). The Hungarian Jesuit was the first to note the southeastern linguistic boundary of the California Yuman groups, a boundary which lay immediately north of Bahía de Los Angeles. At the same time he placed the southernmost extent of dogs and the making or use of pottery on the peninsula in the 18th century. In describing the collection from Bahía de Los Angeles, we have the benefit of ethnographic descriptions from three periods of the Spanish occupation of Baja California prior to 1769 and the expulsion of the Jesuit missionaries. Some historical data derive from the initial voyages of the Spanish along the gulf coast in the 16th century. Later there were occasional contacts with these natives by Jesuit explorers during the first half of the 18th century. Finally, there was the period of active missionization, beginning with the foundation of Santa Gertrudis (1751) and continuing with San Borja (1762) and Santa María (1766). [Illustration: Map 2. Linguistic Groups of Baja California.] Toward the end of the 18th century there are applicable descriptions of Indians immediately to the north by the Dominican priest, Father Luis Sales (1794). The ethnographic information contained in the documents bears out the fact that the cave artifacts belong in the cultural tradition of the Borjeño who inhabited the region at the time of European contact and conquest. THE SITE Bahía de Los Angeles is a semicircular bay, about four miles in diameter, on the gulf coast of Baja California at 28° 55' N. and 113° 30' W. (map 1). On the northwest it is open to the waters of the Gulf of California and to the Canal de las Ballenas, which runs between the peninsula and Isla Ángel de la Guarda, some twelve miles distant. (This island and the smaller Isla Smith obstruct a view of the outer gulf, and from the shore Bahía de Los Angeles appears to be completely landlocked.) Within a few hundred feet of the shore, sandy beaches give way to the talus slopes of the mesas and peaks which edge the bay. An arroyo enters the bay from the west.