1959 Map of Cordova D-1

Glacial meltwater and high-altitude drainage carve the terrain, most notably where the Bremner River flows through Threemile Canyon along the northern edge of the sheet. High peaks are identified by triangulation stations such as VABM 4443 Faust and VABM 4090 Teree, providing essential landmarks for navigation in a region defined by its hydrography, including Eagle Creek and the South Fork.