the photo caption is wall built by immigrants — a bit of vagueness as only the Konkow and the Yana are not recent immigrants. these walls built of volcanic rocks cleared from the fields for cattle grazing once marked property boundaries. they’re known locally as the Chinese walls, built after the railroad was finished by what amounted to slave labor, a story that isn’t actually true, it turns out the rock walls were built by immigrants from the Portuguese Azores. one of the longest walls runs along Highway 32 from Chico to Forest Ranch, taking the path of the old Humboldt Road, the path of stagecoaches to silver mines in Nevada. you can still find places where wagon wheels carved ruts into the bedrock, the Tuscan formation that is only inches below the soil.