By Brendan O'Brien
MILWAUKEE, Dec 9 (Reuters) - The wreckage of a wooden steamship that sank 152 years ago in a storm on Lake Huron with no survivors has been found, a Michigan explorer said on Monday.
What exactly happened to the Keystone State and its 33 occupants in a November 1861 voyage to Milwaukee from Detroit remains a mystery, said David Trotter, who found the wreck with his crew of explorers in July.
The 288-foot side-wheel steam ship hit rough weather and was last seen in a disabled condition off Port Austin on Nov. 8 or 9 in 1861, Trotter said.
"She literally sailed into oblivion. Nobody heard anything from her," Trotter said in a telephone interview.
The wreck was found in 175 feet (53 meters) of water 30 miles (48 km) northeast of Harrisville, a small city north of Lansing. The location put the wreck about 50 miles (80 km) off course.
Trotter, 72, who lives in the Detroit suburb of Canton, Michigan, has found more than 100 shipwrecks on the Great Lakes over the last four decades. In 2012, Trotter and his crew discovered the New York, a 283-foot steamer that also sank in Lake Huron in 1910.
"It's a great chance to touch history to swim back into time," Trotter said of why he searches for shipwrecks.
The Keystone State is one of more than 5,000 shipwrecks on the Great Lakes.
The ship typically moved immigrants to the west and cargo east, according to Trotter. But on its last voyage, it was reported that the ship was carrying farm equipment, odd cargo given the time of the year, he said.
The ship left in hurry with no lifeboats aboard, he added.
"That adds to the mystery of her leaving," Trotter said.
Trotter said legend has it that the ship may instead have been carrying equipment for the Civil War or gold bullion - though he said he has not found military equipment or gold on the wreck. (Reporting by Brendan O'Brien in Milwaukee; Editing by David Bailey and Philip Barbara)