1958 Map of Tyonek A-6

About this map

Blockade Glacier dominates the western portion of this 1950s Alaskan wilderness, where the ice meets a landscape defined by braided river systems and volcanic activity. The Mc Arthur River and Chakachatna River carve through the terrain, depositing silt and creating wide, marshy deltas. High-altitude survey markers like VABM 3213 Chaka and VABM 2351 McArthur help define the dramatic elevation changes from the valley floors to the glaciated peaks. A layer of Volcanic Ash is noted in the northwest, serving as a physical marker of the region's active geology. The map illustrates a transitional environment where heavy glaciation, indicated by dangerous Crevasses, transitions into the lower Straight Creek basin. This survey provides a baseline of the glacial extent and drainage patterns before modern environmental shifts altered the reach of these ice fields.