Mount Diablo is a 3,848-foot peak that dominates the East Bay landscape and lends its name to a region whose history the book traces through settlement, transportation, and suburban growth. It appears both as the outcome of a naming legend rooted in the area’s past and as a landmark beside the valley through which a railway once ran.

Name and Landscape

A local legend places the origin of the name in 1805, when Spanish soldiers pursuing Native Americans reached a willow thicket in what is now Concord. The people they pursued took cover among the dense trees and were gone by the time the soldiers entered. The spooked soldiers named the place Monte del Diablo, with monte then understood to mean woods. Over time, monte came to mean mountain or mount, and English-speaking newcomers transferred the name to the nearby peak. The name thus shifted with the changing meaning of a word, from a thicket where people had disappeared to the prominent landform now called Mount Diablo.

The peak’s name remained a point of public contention. In 2009, local resident Arthur Mijares filed federal paperwork seeking to rename it Mount Reagan because he found the Devil association offensive. His effort did not succeed, leaving Mount Diablo’s established name intact.

The Valley and the Railway

The book places Mount Diablo beside the broad green valley that became central Contra Costa County. Starting in 1891, the Southern Pacific Railroad carried passengers along a twenty-mile route from San Ramon to just north of Concord. Visitors arrived with plans for the abundant land, and development began. When passenger service ended, freight trains continued to carry Bartlett pears, gravel, and sheep; the route became part of everyday life, with its yellow depots, brown trim, and trains passing Murwood Elementary in Walnut Creek as children paused their games to wave at the crews.

That railway landscape gave way to a different kind of development. The completion of I-680 in 1964 represented speed and efficiency, while trucking made freight transport by rail less economical. Train cars dwindled, orchards disappeared, and roofs spread across the valley. The Southern Pacific eventually petitioned to abandon the line, which closed in September 1978, nearly a century after its first track was laid.

Regional Setting in the Narrative

Mount Diablo helps orient the book’s account of the East Bay, but the nearby peak is not presented as the site of the crimes. The narrative instead follows the valley’s towns and routes. Danville, where the East Area Rapist attacked in December 1978, lies within the broader central Contra Costa setting described alongside the mountain’s history.

At the Danville scene, bloodhounds followed a scent along the railroad tracks and stopped about half a mile from their starting point, where the tracks met a residential street. Their handlers believed the suspect had prowled around the area, entered the victim’s backyard over a fence, and left across another fence before continuing south along the tracks, probably reaching a vehicle at the cross street. In this account, the landscape matters through its routes and boundaries: the valley’s former railway corridor became part of the geography investigators tried to reconstruct.