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Lakes / Idaho / Gem County

Lakes in Gem County, Idaho

2 lakes counted in Gem County - the largest is Black Canyon Reservoir at 876.47 acres.

2
Lakes Counted
876.47 acres
Largest - Black Canyon Reservoir

Gem County, highlighted, with its largest counted lakes dotted. Outlines from Census boundary data.

All Counted Lakes

#LakeCountySurface AreaMax Depth
1Black Canyon ReservoirGem876.47 acres-
2Sage Hen ReservoirGem237.6 acres-
Find a Lake in Gem CountyLargest Lakes
Sources: USGS National Hydrography Dataset lake data; USGS. Verified October 30, 2026.