Warren Nickel Prospect

The Warren Nickel Prospect is a real, well-documented mineral locality in Warren, Knox County, Maine — about 500 feet east of Route 131, roughly 0.4 miles south of the Warren-Union town line. It's an ultramafic nickel-cobalt occurrence: pyrrhotite, pentlandite, and chalcopyrite show up as disseminations and massive segregation bodies in andesine-labradorite, hornblende, cummingtonite, and biotite host rock, all sitting within the Ordovician Penobscot Formation. Geologists trace the ore's origin to Late Ordovician emplacement during the Taconic mountain-building event, later reworked by two more rounds of metamorphism. It's called a "prospect" for a reason — this was explored and sampled but never developed into a production mine, and academic literature exists on it (Nickeliferous Pyrrhotite Deposits, Knox County) precisely because it's a documented, if minor, occurrence. No source found confirms current land ownership or whether the old test pits are still visible or accessible.

Warren is a town in Knox County, Maine. The prospect sits roughly 500 feet east of Route 131, about 0.4 miles south of the line where Warren meets Union. UNVERIFIED: no trailhead, parking area, or marked access point was found — this reads as a historically-sampled outcrop/pit area on what is likely private land, not a developed site.

General inference only. A "prospect" like this typically means small pits, trenches, or drill-tested outcrop rather than a worked mine — surface/float picking with hand tools would be the expected method if access is granted. No source confirmed current dig conditions, depth, or season. UNVERIFIED.

Land status is UNVERIFIED. Rural Knox County land near this coordinate is most likely private — confirm ownership and get permission before visiting. This is a scientifically documented occurrence (cited in geological literature going back decades), which makes it a reasonable stop for mineral identification interest, but nothing here suggests it's set up for public collecting.