El Mármol. 1956. "Leaving San Agustín the main road keeps to the right, while an alternate route 8.3 mi. longer goes left to El Mármol (pop. 115), a mining camp owned by the Southwest Onyx and Marble Company. Blocks of high grade onyx are quarried and hauled by truck to San Diego. The quarry was opened shortly after 1900 by an American company which brought a number of Yaqui Indians from Sonora as miners. It is probably the only place in the world that has a school house made of onyx."

Soda spring at El Volcán. 1961.

Agua Dulce. 1952 and 1963.