1926 Map of Boulder Canyon

About this map

Boulder Canyon Dam Site and the proposed Hoover Dam Site represent a critical moment in the history of the American Southwest, appearing here just years before construction began. This survey by the City of Los Angeles focuses on the drainage and topography of the Colorado River and the emerging Lake Mead basin along the Nevada-Arizona border. The map documents the arid terrain of Bitter Spring Valley and Dry Lake Valley, punctuated by landmarks like Muddy Pk and Fortification Hill. Inland, the Union Pacific railroad corridor supports small railway stops such as Apex, Dike, and Garnet. The inclusion of the Boulder Rapids and the settlement of Bonelli provides a view of the river's original state before the massive hydrological engineering projects transformed the region permanently.