1991 Map of Mackay Reservoir

About this map

The Mackay Reservoir serves as the central focal point of this Custer County landscape, held by the Mackay Dam along the course of the Big Lost River. The terrain transitions from the alluvial Cedar Creek Bar in the north to the industrial activity of the southern peaks. Within the White Knob Mountains, an extensive mining history is evident through concentrated excavations and named shafts. The presence of the Empire Mine, Cossack Tunnel, and Darlington Shaft suggests a period of significant extraction in the hills above Rio Grande Canyon. Cultural landmarks include the Battleground Cem near the reservoir's northern reach and several gaging stations monitoring the river's flow through the Challis National Forest. Local irrigation and drainage are detailed by features like the Nielsen Ditch and Sharp Ditch as the water travels southeast toward Swauger Slough.