These were reinforcements to protect Mission San Buenaventura against Mohave (Colorado River) Indians.
Portilla was nominally Commandant of the Presidio of San Diego whenever he was present there, during the years 1835–1838, although he was not stationed there.
He also led a punitive expedition against the Chumash Revolt in Santa Barbara in 1824, traveling to the southern San Joaquin Valley.
For his efforts Mission San Luis Rey de Francia, when secularized by the Mexican Government in 1834, was turned over to Portilla, along with future Governor Pío Pico.
Father Buenaventura Fortuna surrendered Mission San Luis Rey and all its holdings, including Las Flores Estancia and the San Antonio de Pala Asistencia, to government comisianados (commissioners) Pío Pico and Portilla on August 22, 1835; the assessed value of "Rancho de Pala" was $15,363.25.