1989 Map of Devils Slide

About this map

The South Fork Tolt Reservoir dominates this portion of the Snoqualmie National Forest, serving as a critical infrastructure point within the Watershed Boundary (City of Seattle). This 1980s provisional survey illustrates a landscape defined by hydraulic engineering and forest management, where Intake Towers and a Gaging Station monitor the water supply. The terrain rises sharply toward landmarks such as the Devils Slide and the Cascade 3702 Lookout Tower, while the southern reaches are drained by the North Fork Snoqualmie River. Smaller water bodies like Lynch Lake, Black Lake, and the uniquely named Lake Titicaca dot the high elevations. For the researcher, the map preserves the exact locations of service infrastructure like Wagner Bridge and numerous resource extraction sites including quarries and borrow pits that supported the development of this protected watershed.