Twenty-three states and the District of Columbia have now legalized medical marijuana to some degree, but Montana could be the first state to move backwards in allowing access to the drug.

Montana voters legalized medical marijuana in 2004. As recently as 2011, the state of just one million residents had nearly 30,000 patients and 4,900 providers for the drug. But as state legislators cracked down and grassroots opposition has grown stronger, those numbers dropped to 9,000 patients and less than 400 providers in June 2012. There are now 442 providers operating in the state.

The state Supreme Court will make a final ruling as early as October. If the court rules against medical marijuana, providers may be limited to only three patients and banned from advertising. They could also be blocked from charging anything besides $50 license fees and renewals.

"It's hard for patients to live like that, not knowing if they'll have their cards next year," Elizabeth Pincolini, who runs a referral service in Billings, told NBC News.

Part of the crackdown is fueled by the fact that plenty of legal medical marijuana users in the state don’t have a true need for the drug. The opposition movement intensified after pot shops began opening near schools and churches across Montana.

In March 2011, the U.S. Drug Enforcement Administration began conducting raids after it was determined through an 18-month investigation that some medical marijuana businesses were involved in drug trafficking and other federal crimes. Medical marijuana was almost repealed entirely in April 2011 until then-Gov. Brian Schweitzer vetoed the repeal bill.

“You could just see that the traffic going in and out had nothing to do with medicine," said Steve Zabawa, a prominent donor to the anti-marijuana movement in Billings. "Basically, the black market went to the regular market, and it popped up everywhere."

Large providers are still legally allowed to operate, but are unable to refer to their operations as a dispensary, nor are they allowed to call it a business. Other smaller providers have chosen to quietly grow plants for a small clientele, confident that the state Supreme Court will soon rule in their favor and that they will be able to come out of hiding.

"It's interesting that they call 'dispensary' a loaded term," said Carly Dandrea, a "budtender" for Around the Clock Cannabis in Bozeman. "I take offense to that. It's what we do. It's who we are."