Original: In 1769, Gaspar de Portolà during his 1769 expedition of Alta California named it El Río de Nuestra Señora La Reina de Los Ángeles de Porciúncula, so translated: The River of Our Lady Queen of the Angels of Porciuncula.
Simplified: The full name they gave the river was actually El Río de Nuestra Señora La Reina de Los Ángeles de Porciúncula, which translated to English means: The River of Our Lady Queen of the Angels of Porciúncula.