The coordinates provided are believed to be the approximate location of this bridge based on reports by those having trekked into the remains of the 19th-century Tegora Mercury/Antimony Mine site. In general, its location has been a bit of a mystery given its remote location under dense tree cover. It very much appears to be a Harper bridge, but I've never seen it in any list of Harper bridges. Its towers appear almost identical to Harper's Doveridge bridge.