I might postulate that other than Claremont, there aren’t many selective LACs in California. So those who live in CA who want that kind of school, and want to stay “close” have only those to choose from. Those in the east have lots of choices (Amherst, Swat, Middlebury, Williams, Haverford, Wesleyan, Vassar the excellent womens’ colleges… + a whole lot one tiny step down in selectivity.