Rancho Monserate was a 13,323-acre (53.92 km2) Mexican land grant in present-day San Diego County, California, given in 1846 by Governor Pío Pico to Ysidro María Alvarado.
Shortly after bearing three children, Micaela died from unknown causes, and Alvarado married her sister Manuela Lorenzo Avila.
[3] With the cession of California to the United States following the Mexican-American War, the 1848 Treaty of Guadalupe Hidalgo provided that the land grants would be honored.
Tomas Alvarado, present at the ceremony, wrote that, as dirt was being thrown on the casket of Ysidro Alvarado, Couts's brother William Blount Couts and two of his trusted men challenged the mourners from the wall of the graveyard, holding guns and shouting "Como diputado del Sherif del condado, no es permitido que este Señor se entierra aqui" ("As deputy of the sheriff of the county, [I say] it is not permitted to bury this man here.
Colonel Couts explained the incident the next day, saying "In avoiding the loathsome disease now infesting our community, we have had to resort to arms, resulting in the killing of one man.
[10] Tomas Alvarado was born on Main Street in Los Angeles on December 21, 1841, and married María Ygnacia Morena, the widow of Lorenzo Soto, on June 4, 1864.
[11] He received the eastern third of Rancho Monserate in 1874 and built an adobe chapel and a hacienda on the south side of San Luis Rey River.
[10] Dolores Alvarado de Serrano (born 1838) and her husband received the middle third of Rancho Monserate, and built an adobe home in the south part of what is now known as Live Oak Canyon east of Fallbrook.