Disclosures from railroads show they're hauling several dozens of trains carrying volatile crude oil from the Northern Plains through Wisconsin weekly.
State officials released the information in response to an Associated Press public records request.
The disclosures show BNSF Railway has moved up to 42 trains in a week through eight counties along the Mississippi River in western Wisconsin. Canadian Pacific moves up to five trains a week along a La Crosse to Milwaukee route.
Each train can carry about 3 million gallons of oil.
Federal officials ordered railroads to turn over the details to states after a string of fiery accidents, including 47 people killed in a Quebec derailment.
Railroads tried to shield the information from broader disclosure. Wisconsin officials said its release was required under state law.