Petersburg Pilot -

Castle Island Barium-Barite Mine was located in the Kupreanof Mining District from 1966 to 1980 and operated by three companies – Alaska Barite Co., Inlet Oil and Chromalloy America. Castle Island produced about 750,000 metric tons of ore during that time. Mostly a large offshore rock, the site now sits under water.

Barium is critical to well-drilling for the petroleum industry and used around underwater pipelines. It is valuable because of its denseness, chemical inertness, and softness. At present the U.S. is largely dependent on China for its material. The Red Dog District up north i...