Rancho Punta de Quentin was a 8,877-acre (35.92 km2) Mexican land grant in present-day Marin County, California, given in 1840 by Governor Juan B. Alvarado to John B.R.
His Marin holdings also included Rancho Nicasio, which he and Pablo de la Guerra were granted in 1844. Cooper established a lumber business, which he contracted others to run.
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.
[8] Due to illness, bad luck, and poor judgment, Buckelew became embroiled in a series of costly lawsuits, resulting in the loss of all three ranchos.
[9] In 1857, James Ross (1812–1862), in partnership with John and Henry Cowell, bought Rancho Punta de Quentin from Buckelew.