1916 Map of Lone Tree Valley

About this map

Los Medanos and the intricate canyon systems of eastern Contra Costa County define this 1913 survey, published just before the United States entered the Great War. The landscape is primarily shaped by a series of parallel valleys including Horse Valley, Deer Valley, and Briones Valley, which drain toward the northeast. Early industrial activity is evident in Markley Canyon where clusterings of Oil Tanks are recorded near the hills, while the agricultural and ranching character of the region is anchored by local institutions like Deer Valley School and Marsh Creek School. In the north, the Southern Pacific railroad passes through the small settlement of Newlove, providing a vital transportation link for this inland area. The map also clearly delineates the Mt Diablo Base Line, a critical surveying marker for California land titles.