The head of a family-run marijuana operation that grew thousands of plants in three West Michigan counties, preferring heavily-forested sites on federal land, was sentenced this week to more than seven years in prison.

Quinton Allen Mosley Sr., 59, was personally responsible for 1,800 plants harvested and processed for sale, according to court records.

U.S. District Judge Gordon J. Quist on Monday sentenced Mosley to 7-¼ years in federal prison followed by four years of supervised release once he gets out of prison.

Investigators say he and his confederates, including three family members, grew marijuana for nearly a decade in Mason, Oceana and Newaygo counties. Plants were fertilized and trimmed during the summer months until they were ready for harvest at 6 to 7 -feet tall.

Federal investigators charged him with running the conspiracy between 2005 and the fall of 2014. “The principal object of the conspiracy was to make money from the illegal cultivation, harvest, sale and distribution of marijuana,’’ the government wrote.

Mosley Sr. and his confederates planted marijuana in heavily wooded areas of the Huron-Manistee National Forest in Mason and Oceana counties. Plants were also found on private property in Mason County’s Sherman and Freesoil townships and in Newaygo County.

Co-conspirators said the general scheme to plant and grow marijuana on public land began sometime in the late 1990s with Quinton Mosley Sr., who was also joined by his son. The elder Mosley would determine the location of the plots and other members would assist with cultivation and harvest. Much of the post-processing occurred at Mosley Sr.’s home in Hesperia, court records show.

Under a plea agreement, Mosley was allowed to plead guilty to conspiracy to grow more than 100 marijuana plants. He faced a mandatory minimum term of five years in prison and up to 40 years.

A presentence investigator recommended Mosley serve nearly 16 years, which defense attorney David Kaczor said “amounts to a death sentence given Mr. Mosley’s age and poor health.’’

Mosley, who suffers from emphysema and uses an inhaler, “often received help from his brothers to carry marijuana stalks out of the field given the fact he was always short of breath,’’ Kaczor wrote in a sentencing memorandum.

Mosley cooperated with investigators by pointing out drug houses in two separate counties, Kaczor wrote. “Mr. Mosley’s estimate is that he pointed out 20 drug houses and that at least two of these individuals have been arrested.’’

Mosley also denied having a leadership role. “Although the individuals would, from time to time, help each other out, there were no leaders, organizers, managers or supervisors,’’ Kaczor wrote.

He cut and sold firewood as a source of income. He and his wife received public assistance and food stamps, which Kaczor said was “absolutely necessary for the couple’s existence because the large majority of money that Mr. Mosley made by growing marijuana was traded for the other drugs that he was addicted to.’’

Mosley’s involvement in drug distribution stems largely from his own drug addiction for nearly 30 years, which includes marijuana, crack and powder cocaine. “More recently he was heavily involved in the use of morphine, OxyContin, methadone and others,’’ Kaczor wrote. “In fact, a large majority of the money he earned from selling marijuana was used to support his drug habit.’’