Corey Leitz, 41, pleaded guilty to operating a massive marijuana growing operation on Monday.

The Herkimer County resident admitted to setting up and maintaining a marijuana manufacturing operation inside a barn. By December 2011, he had successfully grown over 3,200 marijuana plants.

He then sold the marijuana he manufactured to numerous customers in Herkimer County and elsewhere.

This marks the second felony drug conviction for Leitz, who has a prior drug conviction felony in 1998 in Herkimer County.

A January, 2013, sentencing is scheduled, and Leitz faces a mandatory 20 years imprisonment with a potential maximum of life imprisonment.

Following his incarceration Leitz would be subject to a minimum 10 years of supervised release up to life and a fine of up to $20 million.