At the request of
Manuel Nieto heirs, governor
José Figueroa in 1834, officially declared the
Rancho Los Nietos grant under
Mexican rule and ordered its partition into five smaller ranchos:
Las Bolsas,
Los Alamitos,
Los Cerritos,
Los Coyotes, and Santa Gertrudes. Josefa Cota (widow of Antonio Maria Nieto, son of Manuel Nieto) received the Rancho Santa Gertrudes grant.
Lemuel Carpenter (1808–1859), who had married Maria de Los Angeles Dominguez, a niece of Josefa Cota, bought the rancho in 1843 from Josefa Cota, his aunt by marriage. 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. As required by the Land Act of 1851, a claim for part of Rancho Santa Gertrudes was filed by Lemuel Carpenter with the
Public Land Commission in 1852. Carpenter, who was deeply in debt to
John G. Downey, killed himself in 1859. In 1859 the rancho was sold at a sheriff's auction to Downey and James P. McFarland. of the grant was
patented to McFarland and Downey in 1870. A claim for part of Rancho Santa Gertrudes was filed by Thomas Sanchez Colima with the Public Land Commission in 1852, and of the grant was patented to Thomas Sanchez Colima in 1877. Another claim was filed by Concepción Nieto, but was rejected. The southern border between Ranchos Santa Gertrudes and Los Coyotes exists today as Leffingwell Road. The street Santa Gertrudes Avenue, which runs from
Los Angeles County Route N8 to
California State Route 72, is named after the rancho. ==Historic sites of the Rancho==