Most rare earths on earth? 

CASPER — A mine exploration project in Halleck Creek was ranked as one of the top ten critical mineral sites on the planet after assay results earlier this year revealed exceptionally high levels of rare earth elements.

But this month the project owners, American Rare Earths, U.S. subsidiary of an Australian-founded exploration company, have completed their full development drilling campaign, and the new assay results suggest that soon this Albany County mine will be ranked number one.

Mineral testing of samples from Overton Mountain revealed the site contains even higher concentrations of min...