Indian Population in Southern California Coastal Plain

From pages 4-5 of the 1952 book " The Irvine Ranch" by Robert Glass Cleland:

"At the time of the Spanish occupation of California , there were approximately 250,000 Indians living in the province, a figure that represented about a fourth of the entire native population of what is now continental United States when Columbus discovered the New World . The southern California coastal plain, including present-day Orange County , was one of the major centers of Indian population."

"According to Alfred L. Kroeber, a distinguished authority on the Indians of California, because the Gabrielinos held "the great bulk of the most fertile lowland portion of Southern California " and thus enjoyed a more abundant food supply and easier living conditions than their neighbors, they attained a higher cultural level than any other Indian group south of the Tehachapi and communicated elements of that culture to other villages."