1990 Map of West of Diamond Springs

About this map

The historical Pony Express Trail cuts across the southern portion of this landscape, marking a vital corridor of nineteenth-century communication and travel through the high desert. This 1990 provisional map documents the basin floor of Diamond Valley, a region characterized by expansive Alkali Flat formations and scattered Spring sources essential for transcontinental travel. The eastern edge of the quadrangle is defined by steep elevation gains into the Diamond Mountains, where deep incisions like Box Springs Canyon and Rock Canyon provide a stark contrast to the level valley bottom. This survey preserves the exact alignment of the mail route as it was understood in the late twentieth century, providing a clear reference for those tracing western migration and transportation history through the arid terrain of Eureka County.