The first hint of trouble came in November, when police pulled over a northern Minnesota woman suspected of speeding on Interstate 94 in West Fargo, N.D. While the car was stopped, a police K-9 named Disco hit on something more — packages containing 286 pounds of marijuana with a street value of more than $1.3 million.

A month later, a county sheriff’s deputy made a traffic stop of a minivan driven by a St. Paul man just east of Jamestown, N.D., and discovered nearly 200 pounds of pot.

Then came the stunner. In late January, a routine stop of a truck for a minor driving infraction along I-94 in eastern North Dakota turned out to be anything but. While searching the back of the vehicle, police found 476 pounds of marijuana worth more than $3 million.

The busts, surprising in their worth, have some authorities wondering whether the I-94 corridor that slices through the heart of both states and Wisconsin is becoming a major pipeline for marijuana and other drugs.

“That’s not the direction we want to go,” said Wisconsin State Patrol Lt. Chris Jushka. “We’re definitely seeing more drugs in the state.”

In 2017, Minnesota troopers seized more than 2,600 pounds of marijuana — more than six times what they found the year before. Across the border, North Dakota troopers confiscated 300 pounds in 2017, up 88 percent from 2016. One-third of North Dakota’s drug arrests were made along I-94, authorities say. And in Wisconsin, troopers saw a 20 percent increase in drug arrests, mostly marijuana-related, from 2016 to 2017.

To be sure, the trafficking shows little indication of slowing in 2018.

Several days after North Dakota authorities made the $3 million-plus bust, Minnesota state troopers pulled over a motorist along I-94 in Otter Tail County, and a drug-sniffing dog discovered 200 pounds of marijuana valued at more than $600,000.

Earlier this month, a trooper near Fergus Falls stopped a driver for an obstructed license plate and discovered a passenger sitting on 300 pounds of weed.

Law enforcement in all three states attribute the spike to the fact that marijuana has steadily gained social acceptance in the U.S. and has become partly legal in 29 states, with eight states making it legal for recreational use. In Minnesota, medical marijuana became legalized in 2014, but recreational use here and in North Dakota and Wisconsin remains illegal.

Authorities say they think more residents in the three states are buying marijuana where it’s legal, then bringing it back home to distribute.

“We’ve never had this situation with marijuana laws,” substance abuse expert Carol Falkowski said. “It’s reasonable we’re going to start seeing more of it here.”

North Dakota Highway Patrol Lt. Michael Roark said troopers have made 82 marijuana-related arrests so far this year, often involving drivers passing through to other states.

Minnesota State Patrol Col. Matt Langer wasn’t available for comment last week but told the Star Tribune earlier this month that “we see drugs on every road, but we have seen large quantities in that area and we are paying attention to I-94.”

Brian Marquart, the state Department of Public Safety’s gang and drug coordinator, said authorities have seen a rise in marijuana trafficking across the state over the past several years — from 21,208 ounces confiscated in 2014 to 69,236 ounces in 2017.

“We’re seeing a dramatic increase in marijuana and marijuana concentrate coming from states like Colorado, California and Oregon,” Marquart said, adding that addiction to the drug is “compounded tremendously by public opinion and attitude that it’s not a dangerous substance.”

Slowing the trend

Along with the increase in the amount of marijuana seized of late, Marquart said authorities are also seeing an increase in violent crime.

The Star Tribune reported this month that at least seven Minnesotans died last year during marijuana transactions, the most in a decade.

In Wisconsin, weapons-related arrests increased in 2017 from the year before, as did arrests of drivers under the influence of drugs.

“They generally go together,” Jushka said of drugs, weapons and violence.

Troopers not only are finding more marijuana during traffic stops, he said, but also in the mail.

In an effort to crack down, the Wisconsin State Patrol plans to add another K-9 this week to its force of eight dogs that are trained to sniff out drugs during traffic stops. It also plans to ramp up trooper training.

Minnesota, meanwhile, is adding two dogs to its K-9 unit. It now has 16 dogs, the most it has had in several years. Its canine teams tracked down 2,642 pounds of marijuana in 2017, up from 389 pounds in 2016, according to the State Patrol.

But as with many crime trends, officers say they can’t combat the problem alone.

“It’s aggressive enforcement, but it has to be partnered with a strong prevention message,” Marquart said. “People say that marijuana is a safe substance. … It is very addictive. We just want people to stop dealing and stop using.”