In this text the author, Sherburne Friend Cook, looks at what he sees as a little explored area of the general anthropology and history of California natives, namely the contact between the Spanish-Mexican settlers and the aboriginal population within the Indians' own territory. This contact was achieved through "a constant succession of expeditions, sorties, raids, and campaigns" that came in from the coast. and was documented in reports, diaries, letters. Cook gives the reader valuable access to these documents in a printed format and translated into English.