FILE - In this Sept. 13, 2018, file photo, exploration drilling continues for Permitting Lithium Nevada Corp.'s Thacker Pass Project on the site between Orovada and Kings Valley, in Humboldt county, Nev., shown beyond a driller's shovels in the distance. General Motors Co. has conditionally agreed to invest $650 million in Lithium Americas Corp. in a deal that will give GM exclusive access to the first phase of a mine planned near the Nevada-Oregon line with the largest known source of lithium in the U.S. (Suzanne Featherston/The Daily Free Press via AP, File)