Don’t expect cannabis businesses to start sending truckloads of legal marijuana between these neighboring states anytime soon. (Andy Cross, Denver Post file)

Is transporting marijuana legally between states a pipe dream, or will legalization trend propel change?

Federal law prohibits marijuana and its transportation across state lines; but the new number of cannabis-friendly states sharing borders may end up testing that ban.

America’s historic marijuana legalization experiment has established new cannabis-friendly regions following the elections; but the legalization movement is also entering unknown and uncertain legal territory when it comes to federal vs. state issues regarding interstate marijuana transportation.

As The New York Times notes, more than 20 percent of Americans now live in states where cannabis is or will soon be legal for adult, recreational use. The 2016 elections also created a “marijuana bloc” on the West Coast; starting in Alaska and then stretching all the way down from northern Washington state to Southern California; as well as eastward into Nevada.

California Lt. Gov. Gavin Newsom is quoted by the Times as saying there’s now an opportunity for states where recreational use is legal to “coordinate and collaborate” when it comes to relaxing the federal ban on marijuana.

But don’t expect cannabis businesses to start sending truckloads of legal marijuana between these neighboring states anytime soon.

While the entire Pacific coast of the United States may now be weed-friendly, federal law prohibits transportation of cannabis across state lines. And federal penalties for trafficking marijuana remain harsh: In a worst-case scenario, a first offender convicted of transporting the lowest set amounts of marijuana, hashish or hash oil can face up to five years in prison and fines of up to $250,000.

The federal government also controls interstate commerce, which gives the feds, according to the Canna Law Blog, the “ability to prosecute individuals for transporting marijuana across state lines, even if the transport is from one legal state jurisdiction to another.”

Not every state is strictly following federal law. For example, before Oregon’s recreational sales started in July 2015, police in Portland made it clear their drug enforcement efforts were going toward “large-scale operations,” and not Oregonians going on, say, a cannabis shopping trip in neighboring Washington.

On the East Coast, meanwhile, law enforcement officials in New York state are expressing concerns about the upcoming legalization of recreational cannabis in neighboring Massachusetts.

“I can foresee people going over the border from New York (to Massachusetts) buying an ounce and coming back,” Rensselaer County, N.Y. Sheriff Patrick Russo told WGRZ-TV in Buffalo. “Or I can foresee them going over there and actively smoking it and then driving back under the influence of marijuana.”

That being said, in 2000 the U.S. Supreme Court struck down random police drug checkpoints on highways and roads; ruling that such checkpoints violate the Fourth Amendment‘s guarantee against unreasonable searches and seizures by the government.

And this past August, a federal appeals court in Denver ruled that members of the Kansas Highway Patrol had acted “without reasonable suspicion and violated clearly established precedent” when they stopped and searched a motorist driving a car with Colorado plates — on the apparent presumption a driver from Colorado would be carrying marijuana.

Robert MacCoun, a professor of law at Stanford University, says the issue of cannabis moving between marijuana-legal states will probably remain low priority for local law enforcement.

“Authorities in Oregon are not suddenly feeling threatened by California legalizing, because it’s consistent with their own policy,” he says in a phone interview with The Cannabist. “But it’s Utah and Arizona and other states (where recreational marijuana remains illegal) that you have to worry about.”

Any crackdown on marijuana moving between cannabis-friendly states, he adds, will most likely not be due to “angry state officials complaining about marijuana moving across borders, it’s going to be triggered by zealous federal officials, wanting to reopen this as an issue.”

And given all the political uncertainties surrounding the incoming Trump administration’s stance on marijuana legalization, other experts suggest the legal cannabis industry remain very vigilant.

“They should watch the new administration closely, because they could change or ruin the experiment at any moment,” says William Baude, Neubauer Family Assistant Professor of Law at the University of Chicago.

Speaking during a phone interview with The Cannabist, Baude says he believes Newsom’s concept of states coordinating their marijuana laws is a great idea; so long as those cannabis-legal states “come together to figure out how to contain things” in terms of keeping legal marijuana within their collective borders.

He also suggests keeping the concept of interstate cannabis commerce, as well as further marijuana legalization, from attracting the undo attention of the federal government.

“At the moment we don’t — with the exception of some agricultural inspections in California or Hawaii — we don’t have a tradition of roadblocks or border checkpoints between the states,” he says, “and I think a lot of us would like to avoid having to do that.”

Stanford’s MacCoun says if the marijuana legalization movement is allowed to proceed as it has over the past several years, then the combination of growing industry consolidation and more states adopting cannabis legalization would create new market pressures; an expansion that would be hard to contain within state borders.

“In the long run, if there’s no (federal) backlash, you probably will see the cross-state industry,” he says. “But we’re not in the long run; we’re in a very volatile short run.”