Records on file with Arkansas' emergency managers show that as many as 33 trains carrying Bakken crude oil pass through the state in a given week.
Each train carries at least a million gallons - five times as much crude oil that spilled in Mayflower in March 2013.
Under the Freedom of Information Act, The Associated Press obtained correspondence railroads shared with the state in June. The railroads objected to the materials' release, but federal regulators said the information wasn't "security-sensitive."
Emergency officials say having the information will aid their response if any accident occurs.
The oil trains do not use a Union Pacific rail line that goes through Hoxie, where two freight trains collided Aug. 17, killing two crew members.
