ABOUT 15 MIN AFTER DEPARTING SKAGWAY, WHILE MANEUVERING OVER A GLACIER, THE PILOT NOTED DECREASING ENGINE OIL PRESSURE. SHORTLY THEREAFTER THE ENGINE BEGAN TO EMIT METALLIC SOUNDS, AND THEN THE ENGINE QUIT. AN EMERGENCY LANDING WAS MADE ON THE GLACIER. ON-SCENE EXAMINATION OF THE ENGINE REVEALED THAT THE #2 CYLINDER CONNECTING ROD HAD FAILED. SUBSEQUENT METALLURGICAL EXAMINATION BY THE SAFETY BOARD REVEALED THAT THE FRACTURE OF THE ROD THROUGH THE STRAP AREA ADJACENT TO THE HEAD OF THE ROD BOLT DISPLAYED FEATURES TYPICAL OF A FATIGUE FRACTURE.