SS D. M. Clemson (1903)

SS D. M. Clemson was an American lake freighter in service between 1903 and 1908. She was built by the Superior Shipbuilding Company in West Superior, Wisconsin, for the Provident Steamship Company of Duluth, Minnesota, managed by Augustus B. Wolvin. She was engaged in the iron ore, coal and grain trade, breaking various haulage quantity records on multiple occasions. She was involved in a number of serious accidents, including a collision with the piers of the Ashtabula Harbor Light just a few weeks prior to her loss.

On what was her final voyage of the year, D. M. Clemson locked through the Soo Locks into Lake Superior on the morning of 30 November 1908, with a cargo of coal loaded two days prior in Lorain, Ohio, consigned to Duluth. She was under the command of Captain Samuel R. Chamberlain, who elected to take his vessel on the southernmost route to Duluth, which required passage through the Portage Canal. She was accompanied by the freighter J. J. H. Brown until Whitefish Point, when the vessels parted company. Shortly thereafter, an unusually powerful snow storm descended on Lake Superior, sinking D. M. Clemson, and killing her entire complement of 24.

Within a few days, wreckage was discovered floating in Lake Superior, and on its shores. Initially believed to be from a different freighter, the discovery of several pieces of wreckage bearing a legible name and the confirmation she was the only missing vessel on the lake conclusively identified D. M. Clemson as the source. Contemporary sources speculated she was lost shortly after entering the storm. Her loss has been attributed several different phenomena, including structural or mechanical failure, or the loss of her hatch covers.

Despite repeated searches by the Great Lakes Shipwreck Historical Society, the wreck of D. M. Clemson has never been found. She has been the largest undiscovered shipwreck on the Great Lakes since May 2025.