Oak Flat, near where a copper mine is proposed, is dotted with rugged boulders and desert vegetation. Bri Cossavella/Cronkite News By Anita Snow THE ASSOCIATED PRESS PHOENIX (AP)-Oak Flat, a piece of national forest land in central Arizona, is at the heart of a yearslong struggle between Native American groups and mining interests that both consider it important for their future. Resolution Copper, a subsidiary of international mining giants Rio Tinto and BHP, wants to develop the large deposit of copper ore deep under Oak Flat into a massive mine. The nonprofit Apache Stronghold considers the land sacred and says it should be preserved for religious ceremonies. In a significant blow to Apache Stronghold, a divided federal court panel voted 6-5 on Friday to uphold a lower…