1958 Map of Tyonek A-7

About this map

Lake Clark National Monument encompasses a significant portion of this high-altitude landscape, where massive ice fields and glacial meltwater define the geography. The expansive Chakachamna Lake serves as a central catchment for the surrounding peaks, fed by the Nagish Lamina R and drained eastward by the Chakachatna River. The terrain is characterized by active glacial movement, with the Mc Arthur Glacier, Blockade Glacier, and Barrier Glacier showing numerous crevasses and ice falls. This mid-century survey, based on aerial photography from the late 1950s, records the pristine extent of these glaciers before decades of modern change. The presence of the Mc Arthur River in the southeast corner further illustrates the complex drainage systems that carve through the Alaskan wilderness within the Kenai Peninsula Borough.