HOWELL, Mich. (AP) — Authorities say they’re breaking up a large drug trafficking operation that tried to appear legal under the state’s medical marijuana law.

Lt. James Wolf, section commander of the Western Wayne Narcotics and Criminal Investigations Unit, tells the Livingston Daily Press & Argus that evidence is being sent to the state police crime lab for analysis.

Police expect to present the case, which involves several Livingston County residents, to the state attorney general’s office.

Officers seized 556 plants that Wolf described as being about 8 feet tall and 6 feet wide. Officers also seized assets, including vehicles believed to be used to transport marijuana, as well as an estimated $200,000 in cash and more than a dozen guns.

Michigan voters approved marijuana use for some chronic medical conditions in 2008.