HELENA, Mont. (AP) — As Bob Marley music wailed in the next room, the makeshift clinic hummed along like an assembly line: Patients went in to see a doctor, paid $150 and walked out with a recommendation that they be allowed to buy and smoke medical marijuana.

So it went, all day, at a hotel just blocks from the state Capitol that was the latest stop of the so-called cannabis caravan, a band of doctors and medical marijuana advocates roaming Montana that has helped thousands of patients apply for medical marijuana cards from the state.

"You're helping end suffering on this planet for human beings," clinic organizer Jason Christ said as he sat outside the hotel in an RV filled with pot smoke.

To the dismay of state medical authorities and lawmakers, the caravans have helped the number of pot cardholders in Montana swell over the past year from about 3,000 to 15,000.

Christ's group, Montana Caregivers Network, will take the caravan out of Montana later this month for the first time, with clinics scheduled in three Michigan cities: Detroit, Kalamazoo and Lansing. He said pot advocates from several other states — including New Mexico, New Jersey and Hawaii — have contacted him to inquire about setting up similar businesses.

The state medical board is trying to curtail the mass screenings and recently fined a physician who participated in a similar clinic in the first disciplinary action taken against a doctor in a Montana medical marijuana case. The board found that the doctor had seen about 150 people in 14½ hours, or roughly a patient every six minutes, nowhere near enough to provide appropriate care in the eyes of medical observers.

The board also recently reminded physicians that they must perform thorough examinations, take medical histories, discuss alternative treatments and monitor patients' response to the cannabis — standards that typically apply when prescribing other medication.

"Be on the alert. You are still held to these same standards," said Jean Branscum, the board's executive director.

The roving cannabis caravans appear to be unique to Montana, although mobile marijuana operations have arisen elsewhere. A rolling marijuana dispensary in California sold chocolate-covered cookies, brownies, pretzels and other marijuana-laced items out of an RV before authorities moved to shut it down.

Mike Meno, spokesman for the Marijuana Policy Project, the chief lobbying arm of the legalization movement, said the 14 states that allow medical marijuana have varying regulations that could make it difficult for the caravans to operate outside Montana.

"The more I hear about these things, it sounds like they're not following the intent of the law," Meno said. "People say they might be making a mockery of the law, and I hope that's not the case."

Medical marijuana has been legal in Montana for more than five years, allowing people with debilitating conditions to buy pot with a doctor's permission.

After the Obama administration announced last year that it would not prosecute medical marijuana users, the pace of registrations quickened, and people began flocking to the caravans.

At a recent stop in Helena, the clinic processed between 200 and 300 people seeking doctor recommendations. The organization then helps the patient send the application and doctor's recommendation to the state health department. After the patient receives a card, he can begin using marijuana.

In the hotel conference room, when patients emerged from behind a curtain after talking with a doctor, they were ushered to the next room, where a half-dozen marijuana providers competed to become their personal "caregiver," as the suppliers are called in Montana.

A group called the First Montana Grow Circle signed up 15 new patients that day. One of them was a state employee who spoke on condition of anonymity because she feared repercussions from her employer and her family.

She said she went to the clinic during her lunch hour after her personal doctor declined to prescribe medical marijuana for her severe migraine headaches. "He said I am not the type of person he would prescribe it for. He said I'm not there yet based on my medical history," the woman said.

She said the doctor at the clinic gave her the recommendation she was looking for after a 15-minute examination and a promise to send him her medical records. She said the marijuana has eased but not eliminated her headaches.

The Montana Board of Medical Examiners fined Dr. Patricia Cole $2,000, accusing her of practicing substandard care at a medical marijuana clinic in Great Falls last year. The caregivers' network is paying her fine. She is also barred from participating in such clinics.

The board said Cole did not document whether she took medical histories or performed physical examinations, did not discuss proper dosing and failed to document a risk analysis of medical marijuana for them.

Cole said she agreed to the punishment, but believes she is being made an example of as the board seeks to halt the caravans. She said she reviewed medical histories online before the clinic.

At the same, some lawmakers say the clinics demonstrate the pot boom is out of control and the rules need tightening.

Despite the warnings and the disciplinary action, the cannabis caravans are slated to roll on next month with stops in Kalispell, Missoula, Great Falls, Helena, Bozeman and Billings.

"Change is scary. I understand," Christ said of the backlash. But he added: "The need is out there. Patients are in pain."

(This version CORRECTS that patients receive a recommendation, but still must await formal approval to buy and use pot.)