Oklahoma emergency officials say as many as seven trains a week pass through the state carrying crude oil from the Northern Plains that's been involved in fiery derailments, including a 2008 explosion northeast of Oklahoma City.
Some of the trains are travelling through the state's two most populous counties: Oklahoma County, with one train a week, and Tulsa County, with four.
In August 2008, an oil train that originated in Fairview, Montana, derailed near Luther, causing an explosion and fire involving more than 80,000 gallons of crude.
Responding to public records requests, Oklahoma's emergency response commission on Monday disclosed the number of trains expected through 20 counties. It did not name the railroads involved.
Railroads provided details on the shipments to states in June under a federal order.