text: The Mountain Pass deposit was discovered in 1949 by Herbert S. Woodward, Clarence Watkins and P. A. Simon, who noticed anomalously high radioactivity. Molybdenum Corporation of America bought most of the mining claims, and began small-scale production in 1952.
  Production expanded greatly in the 1960s, to supply demand for europium used in color television screens. Between 1965 and 1995, the mine supplied most of the worldwide rare-earth metals consumption.
  Molybdenum Corporation of America changed its name to Molycorp in 1974. The corporation was acquired by Union Oil in 1977, which in turn became part of Chevron Corporation in 2005.
  In 1998, the mine's separation plant ceased production of refined rare-earth compounds; it continued to produce bastnäsite concentrate.
  The mine closed in 2002 after a toxic waste spill and wasn't reopened due to competition from Chinese suppliers, though processing of previously mined ore continued.
  In 2008, Chevron sold the mine to privately-held Molycorp Minerals LLC, a company formed to revive the Mountain Pass mine. Molycorp announced plans to spend $500 million to reopen and expand the mine, and on July 29, 2010, it raised about $400 million through an initial public offering, selling 28,125,000 shares at $14 under the ticker symbol MCP on the New York Stock Exchange.
  In December 2010, Molycorp announced that it had secured all the environmental permits needed to build a new ore processing plant at the mine; construction would begin in January 2011, and was expected to be completed by the end of 2012. On August 27, 2012, the company announced that mining had restarted.
  The processing plant was in full production on June 25, 2015, when Molycorp filed for Chapter 11 bankruptcy with outstanding bonds in the amount of $US 1.4 billion. The company's shares were removed from the NYSE.
  In August 2015, it was reported that the mine was to be shut down.
  On August 31, 2016, Molycorp Inc. emerged from bankruptcy as Neo Performance Materials, leaving behind the mine as Molycorp Minerals LLC in its own separate Chapter 11 bankruptcy. As of January 2016, its shares were traded OTC under the symbol MCPIQ.
  Mountain Pass was acquired out of bankruptcy in July 2017 with the goal of reviving America's rare-earth industry. MP Materials resumed mining and refining operations in January 2018.