1958 Map of East Portal

About this map

The Continental Divide defines the spine of this high-altitude landscape, separating the drainage of Hamilton Creek and Cabin Creek to the west from the South Fork Boulder Creek to the east. At the center of the sheet, the Rollins Pass (Site) marks a critical historical crossing point where the Boulder Wagon Road met early rail infrastructure. By the late 1950s, the engineering marvel of the Moffat Tunnel had transformed the region's transport, with the East Portal serving as a focal point for the Denver and Rio Grande Western railroad operations. The map details the intricate path of the Corona Trail and the dramatic looping rail alignment at Riflesight Notch, reflecting a period when remote mountain passes were being actively studied at sites like the Corona Range Study Plot. High-basin features such as Skyscraper Reservoir and Yankee Doodle Lake illustrate the management of alpine water resources across the Arapaho National Forest and Roosevelt National Forest.