Fifty oil trains, each loaded with more than 1 million gallons of North Dakota crude oil, pass through Minnesota each week, and almost all of them go through the Twin Cities, according to the first detailed reports on the state's crude-by-rail traffic obtained by the Star Tribune.

The reports, submitted to state officials by railroads and stamped "confidential,'' say that oil trains can be more than 100 tank cars long as they pass through 39 of the state's 87 counties. The greatest concentration is on the BNSF Railway main line between Moorhead and the Twin Cities. Canadian Pacific, another railroad serving North Dakota's Bakken region, sends far fewer oil trains through the state, the data show.

Almost all of the oil trains pass through populated areas. Ramsey County and Clay County, which borders Fargo, N.D., have the most traffic — 45 per week on average. In the seven-county metro area, every county except Scott and Carver sees at least 40 oil trains per week.

"We are getting a fuller picture of what is actually passing through our communities that have densely populated areas right next to these rail lines," Rep. Frank Hornstein, chairman of the Minnesota House transportation finance committee, said of the state's decision to release the oil train data.

Before now, state officials have said only that seven or eight oil trains run daily through the state. The detailed county-by-county information had been declared nonpublic by the state Public Safety Department until the Star Tribune asked officials to reconsider that classification.

Minnesota's disclosure comes two days after U.S. transportation officials announced draft regulations to retrofit or retire thousands of older tank cars to reduce accident risks from crude oil and ethanol trains. At least 15 major accidents involving crude oil or ethanol trains have occurred in the United States and Canada since 2006. The worst was just over a year ago in Lac-Mégantic, Quebec, where a runaway oil train derailed, exploded and burned, killing 47 people.

At least 10 other states, including all of Minnesota's neighbors, have already disclosed details about oil trains crossing their states. Railroads in May were ordered by the U.S. Transportation Department to supply states with information about trains carrying at least 1 million gallons of Bakken crude oil.

BNSF and Canadian Pacific, whose U.S. headquarters is in Minneapolis, had pushed state officials not to disclose the oil train information. On Friday, Minnesota Public Safety Commissioner Mona Dohman reviewed the state's position and concluded the information is public under a recent Federal Railroad Administration declaration that it's not sensitive security data.

The reports, which pre­sent the train counts as weekly averages, noted that traffic can vary from week to week.

Where do they go?

Almost all of the oil trains passing through Minnesota cross into Wisconsin, traveling along the Mississippi River before turning east, often to East Coast oil refineries. About three oil trains a week travel BNSF's tracks through the far southwest corner of the state, where rail lines lead into Iowa or South Dakota.

Duluth and Rochester have no Bakken oil train traffic, according to the reports. But Dave Christianson, senior rail planner for freight at the Minnesota Department of Transportation, said a few trains carrying crude oil from Canada pass through Duluth on another railroad. They're not in the reports because the federal order applies only to Bakken crude. Ethanol trains also are not counted in the reports, but state officials have said they also pass through the Twin Cities.

Moorhead is a major crude oil crossroads for BNSF, the reports show, with 10 oil trains per week going southbound out of the area, and another 35 trains per week heading east. Eventually, most of the shipments pass St. Cloud, where BNSF tracks parallel Hwy. 10 into Anoka County. Exact routes are not specified in the reports, however.

After passing through the Twin Cities, oil trains head southeast along the Mississippi, where BNSF owns tracks on the Wisconsin side and Canadian Pacific owns tracks on the Minnesota side.

But Canadian Pacific reported only four North Dakota oil trains per week passing through the metro area and then going southeast through Dakota, Goodhue, Wabasha and Winona counties. BNSF reported 10 times that number through the Twin Cities and onto its Wisconsin trackage.

Neither BNSF nor Canadian Pacific would comment on the reports Friday, but both railroads said they have taken steps to improve rail safety. They also have policies to encourage shipment of oil in newer,more-robust tank cars.

"[Canadian Pacific] has undergone comprehensive companywide strengthening of our operating rules and employee training," said Canadian Pacific spokesman Ed Greenberg. "We have increased track and train inspections across our network, including through the state of Minnesota. … We really have redoubled our efforts around emergency preparedness, including collaborations with local first responders and planning and training."

Under a 2014 state law sponsored by Hornstein, Minnesota also is adding new rail inspectors and taking other steps to address oil train risks. Christianson of MnDOT said two inspectors plus a new hazmat expert will be hired within weeks. Meanwhile, the state Transportation Department is studying the risks of 500 road crossings on railroad tracks that carry oil trains, he said. The goal is to identify the highest-risk intersections, and invest in safety improvements.

Hornstein said that when it comes to oil trains, both the state and federal government need to increase oversight of railroads, including requiring disclosure of more precise routes and times to local officials.

But he said the release of the county-by-county data is a positive development.

"I think it should be taken a step further," he said.

David Shaffer • 612-673-7090 • @ShafferStrib