Saginaw Development Company started sinking the Saginaw Shaft on April 12, 1904, after they purchased the World’s Fair mine and group of claims. During, September of 1904 chalcocite samples from the Saginaw were being shown around Bisbee. Even though, the newspaper Iron Ore from Ishpeming, Michigan was critical of how slow the Saginaw shaft was being sunk, by March the following year the three compartment shaft was 747ft. deep. Also, the 350ft. level was being developed with the intent of connecting to the World’s Fair Mine. In 1905 just at 776ft. water was hit and the company sank to 800 level.  Sinking stopped at the time and the company discussed sinking a second shaft down in the “flats” to be used as a pumping shaft to drain the ground around the Saginaw shaft. Although this was not done at the Saginaw, this technique was used at the Junction shaft to drain the Briggs and Hoatson mines.  Early in March of 1906, the American Development Company Merged with the Saginaw Development Company to form The American-Saginaw Development Company. This new corporation continued to operate and was able to sink the shaft to the depth of 920 ft.   The mine was sold to the Calumet & Arizona Mining Company in February of 1913. It was not until 1929, that the mine became active again. The hoist and steel headframe from the Irish Mag mine was moved and installed on the Saginaw. During the following year, the shaft was sunk 829ft., further to a total depth of 1,744ft.   Importantly, during 1937 the collar of Saginaw shaft was concreted and two years later the shaft was retimbered and gunited. In 1943 the Saginaw hoist was removed and sent to the 2100 level of the Campbell Mine to aid in the sinking of the Campbell Shaft from the 2700 level to the 2966 level.  An another used hoist purchased from Del Norte Leasing Company was installed at the Saginaw and a connection was made from the Campbell mine to the Saginaw to ventilate the 2700 level Campbell. The Saginaw continued to be used for ventilation until the mines closed in 1975.  For a decade after the mines closed the Saginaw remained largely intact with its headframe and hoist. The shaft itself had been covered with a concrete cap.  During the 1990’s the hoist house was torn down and the hoist removed. Today, the Saginaw headframes still stands without sheave wheels.  All levels below the 760 are underwater.