Question: Which mine in California, lasting from 1873 to 1883, became one of the most noted mercury producers in the world?
Sentence (from "Helvetia, Pennsylvania"): It had three periods of ownership; Adrian Iselin built the town and started commercial operations at the mine around 1890–1891; during the second period of ownership, from 1896 to 1947, management and operations at Helvetia were under the direct control of the R&P; in 1947, the R&P sold all of its company towns, including Helvetia, to the Kovalchick Salvage Company.
Relevant evidence: No