Grummett-Knox Mine Group

Past ProducerManganese, SilicaSurface-UndergroundUSGS MRDS

Location

StateCalifornia
CountyStanislaus
Coordinates37.52522, -121.34822

Commodities

TertiaryManganese, Silica

Mine Details

StatusPast Producer
TypeSurface-Underground
First Production1918
Discovery Year1918
Data SourceUSGS MRDS
Source ID10117875

What This Means

This mine is a past producer — it was once operational but is no longer actively mining. Past producer sites may still have environmental impacts including disturbed land, tailings piles, and potential water quality effects. Some past producer sites have been reclaimed, while others remain as-is. Check with your state mining or environmental agency for current site conditions.

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