Coal Mine No. 8: a St. Charles coalfield survives at Hartley
St. Charles grew at the center of the Saginaw Valley coalfield; today Coal Mine No. 8 survives as a historical site and museum at Hartley Outdoor Education Center.
Most people do not think of Michigan as coal country, but St. Charles once sat in the middle of a busy coalfield. A state historical marker says dozens of mines opened across Bay, Saginaw, and Shiawassee counties in the 1890s. St. Charles grew past 1,000 residents by 1900, and the state coal mine inspector kept an office there for years.
The boom did not last. Labor strikes after World War I and diminishing returns from the mines pushed the industry into decline. Swan Creek Mine, the last producing coal mine in Michigan, closed in 1952.
Coal Mine No. 8 remains part of the landscape at Hartley Outdoor Education Center. Saginaw Intermediate School District operates the 311-acre center and lists the mine as a historical site and museum alongside its cabins, schoolhouse, farm, woods, wetlands, and ponds. Generations after the coalfield went quiet, students still meet that piece of St. Charles history on a field trip.
Sources
Last reviewed against the listed sources: July 12, 2026.