1970 Map of Dillon

About this map

The Blue River corridor in the early 1970s reflects a landscape defined by the arrival of the Dillon Reservoir, with the settlements of Silverthorne and Dillon positioned at this major hydrological junction. Steep terrain dominates the eastern portion of the sheet, where the Williams Fork Mountains and Arapaho National Forest are crossed by the Williams Fork Pack Trail. This era shows the valley in a state of transition; while rugged peaks like Ptarmigan Peak and Tenderfoot Mountain remain constant, the valley floor features modern utility infrastructure like sewage disposal ponds alongside industrial gravel pits. Local landmarks such as the Blue River Ranch Lakes and numerous drainages like Maryland Creek and Straight Creek provide fine-grained detail for those studying the evolution of Summit County’s topography and early recreational development.