Rancho Cañada de los Osos y Pecho y Islay

It includes the southern part of Montaña de Oro State Park and the site of the Diablo Canyon Power Plant.

In 1845, Wilson moved his family from San Luis Obispo to Rancho Cañada de los Osos y Pecho y Islay, built an adobe home, and lived there until his death in 1860.

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.

In 1901, Henry Cowell of San Francisco acquired a note of indebtedness on the Hilliard property and took control of the remaining Pecho ranch.

The Marre property was leased by Pacific Gas and Electric Company for the Diablo Canyon Power Plant.

The Pacific Ocean coastline from Valencia Peak, in present-day Montaña de Oro State Park. All of the land in this photo was part of the old Rancho Pecho y Islay.
Old Spooner Ranch House, living history program, 2005
Site of the historic Pecho Ranch Reservoir, Reservoir Flats Trail, Montaña de Oro State Park