A Riverton man arrested in December for allegedly growing hundreds of marijuana plants pleaded not guilty in federal court on Friday.

Luke Jackson Tilghman, 33, entered the plea before U.S. Magistrate Judge Michael Shickich during his arraignment.

He remains in custody.

In January, a federal grand jury indicted Tilghman with one count of possession with intent to distribute 100 or more plants. The U.S. Drug Enforcement Agency regards marijuana as a Schedule I controlled substance, meaning it is a drug “with no currently accepted medical use and a high potential for abuse.”

If convicted, federal sentencing guidelines state he would serve not less than five years and not more than 40 years imprisonment.

Tilghman’s name surfaced during the investigation of a Casper with his own marijuana growing operation in Paradise Valley.

The case started Dec. 14 when investigators with the Wyoming Division of Criminal Investigation and the Casper Police Department learned of a large marijuana growing operation at 372 Oleander St., according to court records.

Two days later, authorities searched the residence, found a multistage growing operation, and collected 54 suspected plants. Buds of the plants weighed more than 375 grams without packaging.

Neil Arcuri, 35, was charged in state court with one felony count of possession of a controlled substance, one felony count of possession a controlled substance with intent to deliver, and one misdemeanor count of cultivating a controlled substance.

In April, Arcuri pleaded guilty to one count of possession of a controlled substance. As part of a plea deal, prosecutors dropped two other charges against him, and will seek a term of probation.

During the investigation of Arcuri, authorities found information about another growing operation and passed it to other authorities.

On Dec. 17, they executed search warrants at two places in Fremont County and seized approximately 640 high-grade marijuana plants, additional bulk marijuana, and an undetermined amount of cash.

Tilghman was arrested on other charges.