The Pittsburg & Duluth Mining Company started sinking the Congdon shaft in March of 1903 on the Black Bear claim.  The work proceeded rapidly and by 1904 the shaft was 1,266ft. deep. J.H. Silvia was the foreman at the mine and lived only a few hundred feet from the mine. The 1050 level was connected to 850 level Irish Mag/ Oliver mine workings with an agreement from the Copper Queen Consolidated Mining Company that allowed the company to drive 600ft. of drift through Copper Queen’s Lucky Jack Claim. This and another connection to the 1000 level of the Oliver Mine to the 1250 Congdon provided essential air flow.  Later the #2 crosscut on the 1250 level was driven towards the Cole Shaft of the Lake Superior and Pittsburg Mining Company. It connected to the Cole’s 1350 level with a raise. While driving this crosscut supplied ore was unexpectedly discovered. Some oxide ores were also discovered as samples crystallized native copper with cuprite from the mine were proudly shown around Bisbee. The main ores discovered were on the Sunnyside claim, which lies halfway between the Cole Shaft and the Congdon. Due to this it was decided to shut down the Congdon in 1905, . The Cole Mine was already built to handle ore and already had a rail line to the mine site. The mine was still credited for producing ore in 1906. During this year the Congdon was shipping 150 tons daily, but the Congdon shaft itself remained inactive. This ore was mainly removed through the Cole Shaft. A smaller amount was removed though the L.S.&P.#3 shaft in 1904-1905, while the Cole shaft was being enlarged to four compartments and the mine site was renovated. During 1906, the Pittsburg & Duluth Mining Company merged with the Calumet & Pittsburg, the Lake Superior & Pittsburg and the Junction Mining Company to form the Superior and Pittsburg Copper Company. New company developed the Congdon ores on the Sunnyside claim into what was one of the largest orebodies in the district, but these were mined through the Cole. In 1943, a drift driven from the Cole 800 level intercepted the 1250 level for ventilation. The Congdon served as a source of ventilation until the mines shut down in 1975. In the 1990’s the Congdon was an overgrown, raw shaft that was protected by a sheet metal fence. Some massive pyrite could be found on the dump, hinting at the sulfides below.