1954 Map of Ontario

About this map

Ontario and its surrounding citrus and industrial heartland sit at the base of the San Gabriel Mountains in this mid-century survey. The landscape is defined by the rigid grid of agricultural and suburban expansion, anchored by the growing Ontario International Airport and a dense network of major railroads including the Southern Pacific and Union Pacific. North of the developing urban cores of Upland and Claremont, the terrain rises sharply into the Angeles National Forest, where deep incisions like San Antonio Canyon and peaks such as Cucamonga Peak dwarf the valley floor.