 The Gabrieleño territory was the center of a flourishing trade network that extended from the Channel Islands as far east as the Colorado River, allowing the Gabrieleño to maintain trade relations with the Cahuilla, Serrano, Luisenio, Chumash, and Mojave cultural groups.The earliest ethnological surveys of the Christianized population of the San Gabriel area, who were then known by the Spanish as "Gabrielino", were conducted in the mid-19th century.By this time, their pre-Christian religious beliefs and mythology were already fading.