The tall smokestack at Croft Mine Historical Park symbolizes the era when men worked with picks and shovels, sometimes more than six hundred feet below the surface, to meet daily iron ore production quotas. In 1914, the Merrimac Mining Company, under the leadership of John A. Savage, began work on the Croft Mine north of Crosby, tapping the same ore body as the Armour No. 2, Thompson, and Meacham mines. The smokestack's footing, measuring 28 feet square by 12 feet deep, was hand-dug by a crew of four or five men. A circular concrete shaft was sunk through 110 feet of surface drift to solid ledge, and from there a rectangular steel-encased shaft was driven to a depth of 250 feet. In 1916, the Croft's first shipping year, its high-grade ore averaged 59.7 percent iron, and by its closure in 1934, the mine had shipped a total of 1,700,699 tons. Later recognized as an example of the underground mining era, the site was purchased by the State of Minnesota in 1978, dedicated as a park in 1980, and included in the Cuyuna Country State Recreation Area and the National Register of Historic Places.