sorry I misspoke, not bloomberg article, a Defense News article about the California mine:
https://www.defensenews.com/opinion/commentary/2019/11/12/the-collapse-of-american-rare-earth-mining-and-lessons-learned/
Map 1:
https://pubs.usgs.gov/sir/2010/5220/
Map 2:
https://mrdata.usgs.gov/ree/map-us.html
A good read. China has been buying mining assets in other countries unabated. I remember Molycorp and a few others. the last administration was out to lunch on this issue.