The SS St. Marys Challenger is a freight-carrying vessel operating on the North American Great Lakes built in 1906.

After a 107-year-long working career as a self-propelled boat, she was converted into a barge and paired with the tug Prentiss Brown as an articulated tug-barge.

The shipyard had received an order to construct a 551-foot (168 m) Great Lakes bulk carrier for what was then the booming Minnesota iron ore trade.

William P. Snyder was beginning her working life at the same time as the development of the assembly line for bolting together consumer goods made with steel, such as automobiles.

Elton Hoyt 2nd was repowered in 1950 with a Skinner Unaflow steam engine and two watertube boilers by the Christy Corporation of Sturgeon Bay, WI.

[1] During her second half-century of life the vessel became a favorite of boatwatchers up and down the Great Lakes as a final example of the riveted steamships of the Second Industrial Revolution.

[2] The tug Prentiss Brown had been built in 1967 at the Gulfport Shipyard in Port Arthur, Texas and worked in Florida, South Carolina, and New York before coming to the Great Lakes in 2008.