According to a news story in the Denver Post, authorities say Colorado is becoming a major exporter of illegally grown marijuana to the rest of the country.

A new report from a network of law enforcement organizations presents in detail police reports from 2012. Last year alone, police across the country made at least 274 highway seizures of marijuana that investigators linked back to Colorado.

According to the report, 3 ½ tons of pot was seized from Colorado in 2012, and was destined for 37 different states, most frequently Kansas, Missouri and Illinois.

According to the Denver Post, the law enforcement report stated that officers also seized hundreds of thousands of dollars connected to the cases, and that some of the seized marijuana was diverted from medical marijuana dispensaries.

The Denver Post story also reported that U.S. Postal Service inspectors in 2012 seized 158 packages of marijuana being sent through the mail, and that 209 packages of pot were seized in mail deliveries during the first five months of 2013.

The law enforcement report was written by the Rocky Mountain High Intensity Drug Trafficking Area, which is made up of a network of law enforcement organizations in four western states. The organization shares information on drug-running patterns.

According to the Denver Post, the report is preliminary, and the numbers come from a database kept by the Department of Justice’s El Paso Intelligence Center, to which law enforcement agencies report seizure information.