2019 Map of McGrath D-1 SE

About this map

The Little Tonzona River carves a central path through this subarctic terrain in the Yukon-Koyukuk region. In this part of the Alaska Interior, the hydrology is defined by the braided path of the river and the incoming waters of the Clear Fork. The map provides a look at the natural state of this drainage system before any major infrastructure, highlighting the complex network of mountain streams and topographic contours that dictate the flow toward the Tanana valley. This 2019 data captures the landscape at a point where traditional surveying boundaries like t32n r21w and t31n r20w meet the raw geographic reality of the river's winding course.