Excerpted from the following report:

The report says one of the most promising sites is Bokan Mountain on the southernmost island of Alaska. Ucore Rare Metals has been exploring there since 2007, and the region was once home to a uranium mine, so some infrastructure is already in place, together with a deep water port.

http://www.newscientist.com/article/dn19753-us-reserves-of-rare-earth-elements-assessed-for-first-time.html