1986 Map of Seven Lakes Basin

About this map

Seven Lakes Basin sits at the geological intersection of the Trinity Mountains and the headwaters of several major California waterways in the mid-1980s. This survey records a landscape defined by high-altitude glacial cirques and alpine lakes, including Castle Lake, Lake Helen, and the clustered Upper Seven Lake and Lower Seven Lake. The drainage patterns are significant here, showing the origins of the Sacramento River and its South Fork alongside the South Fork Trinity River and Tamarack Creek.