Rancho Los Medanos
Rancho Los Medanos (from the Spanish: Rancho Los Medaños meaning Sand Dunes Ranch) was a 8,859-acre (35.85 km2) Mexican land grant in present-day Contra Costa County, California given in 1839 by Governor Juan Alvarado to Jose Antonio Mesa and Jose Miguel Garcia. The name "los medanos" is derived from the sand hills located along the San Joaquin River on its northern boundary. Rancho Los Medanos was located at the junction of the San Joaquin River and the Sacramento River, extending eastward along the south shore of Suisun Bay to Antioch. The rancho lands included present-day Antioch and Pittsburg.
The two league Rancho Los Medanos was granted in 1835 to Jose Antonio Mesa and Jose Miquel Garcia. Jose Antonio Mesa was the son of Corporal José Valerio Mesa who came to California with the Anza Expedition. Jose Antonio Mesa's son, Juan Prado Mesa, was the grantee of Rancho San Antonio.
Mesa and Garcia sold the southern half of their rancho to Colonel Jonathan D. Stevenson in 1849, and the northern half to James Walsh, Michael Murray, and Ellen Fallon in 1850. There was confusion about the orientation of the grant, and in 1851 Stevenson arranged an exchange of deeds, whereby he got the west half of the rancho, and Walsh, Murray, and Fallon got the east half.
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. A claim was filed with the Public Land Commission in 1853, and the grant was patented to Jonathan D. Stevenson et al. in 1872. A claim for Rancho Los Medanos filed in 1853 by James Enright, Michael Murphy, and Ellen Fallon, was rejected.
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