Complex sentence: Writers passed through the San Jacinto valley where the Luiseňo were settled and recorded much of their culture, and along with missionaries and soldiers were a part of the 1776 Juan Bautista de Anza expedition overland to and through Las Californias sponsored by Spanish monarchy.
Split into simpler sentences: Writers passed through the San Jacinto valley where the Luiseňo were settled and recorded much of their culture. Along with missionaries and soldiers were a part of the 1776 Juan Bautista de Anza expedition overland to and through Las Californias sponsored by Spanish monarchy.