The vessel was launched on February 7, 1906, by Great Lakes Engineering Works in Ecorse, Michigan.
The shipyard had received an order to rivet together the plates of a 551-foot (168 m) hull for what was then the booming Minnesota iron ore trade.
Soon the large boat, christened William P. Snyder, was shuttling hematite for the Shenango Furnace Company.
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.
Iron ore boats would have plenty of work to do.
William P. Snyder also carried iron ore to furnaces to make munitions used in World War I and World War II.

Originally powered by two Scotch boilers, the vessel, by now renamed Elton Hoyt II, was repowered in 1950 with a Skinner Unaflow steam engine and two watertube boilers.
This would be the first of five separate renamings as the vessel repeatedly changed owners.
Too small by the 1960s to serve as a profitable ore boat, the vessel was laid up and then, in 1966, plucked out of a freshwater boneyard for reconversion and new life as a cement carrier for the Medusa Portland Cement Co. Now based in Charlevoix, Michigan and named Medusa Challenger, the aging steamship shuttled powdered cement from Northern Michigan to a wide variety of roadbuilding contractors in various port locations on the Great Lakes.
In Chicago she acquired a reputation as a "jinx ship" that caused the city's drawbridges to become stuck when they were raised to let her pass, causing long delays to traffic.
Such an incident became the setting for the 1977 dramatic film Medusa Challenger.
In 1998 the Medusa Corporation was acquired by Southdown Inc., of Houston and the vessel was renamed Southdown Challenger.
After two more acquisitions, the vessel became the property of St. Marys Cement Inc. of Toronto in 2005 and finally renamed St. Marys Challenger.

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.
The vessel was launched on February 7, 1906, by Great Lakes Engineering Works in Ecorse, Michigan. The shipyard had received an order to rivet together the plates of a 551-foot (168 m) hull for what was then the booming Minnesota iron ore trade. Soon the large boat, christened William P. Snyder, was shuttling hematite for the Shenango Furnace Company. 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. Iron ore boats would have plenty of work to do. William P. Snyder also carried iron ore to furnaces to make munitions used in World War I and World War II.
Originally powered by two Scotch boilers, the vessel, by now renamed Elton Hoyt II, was repowered in 1950 with a Skinner Unaflow steam engine and two watertube boilers. This would be the first of five separate renamings as the vessel repeatedly changed owners. Too small by the 1960s to serve as a profitable ore boat, the vessel was laid up and then, in 1966, plucked out of a freshwater boneyard for reconversion and new life as a cement carrier for the Medusa Portland Cement Co. Now based in Charlevoix, Michigan and named Medusa Challenger, the aging steamship shuttled powdered cement from Northern Michigan to a wide variety of roadbuilding contractors in various port locations on the Great Lakes. In Chicago she acquired a reputation as a "jinx ship" that caused the city's drawbridges to become stuck when they were raised to let her pass, causing long delays to traffic. Such an incident became the setting for the 1977 dramatic film Medusa Challenger. In 1998 the Medusa Corporation was acquired by Southdown Inc., of Houston and the vessel was renamed Southdown Challenger. After two more acquisitions, the vessel became the property of St. Marys Cement Inc. of Toronto in 2005 and finally renamed St. Marys Challenger.
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.
SS St. Marys Challenger