Located northwest of the Cole shaft, the Cole adit was started by Phelps Dodge on September 20, 1946 and by 1947 3,966ft. of drift had been driven. During this time, the Powell shaft was intercepted 25ft. below the 400 level. Diamond drills stations were cut and drilling discovered some mineralized ground on the Illawarra and Lucky Claims. In an attempted to modernize Bisbee mining, the adit was driven in 12’X 12’ crosscuts with 60lb rails. Unfortunately, the adit failed to uncover any significant ore mineable at its level. In 1948 the exploration in the Cole adit ceased. During the 1990’s the adit was gated but remained open.