Cheese thieves are on the prowl in the Dairy State.

A thief swiped 40,000 pounds of Minnesota-made Parmesan valued at $90,000 from a distribution center in Marshfield, Wis., earlier this month. The cheese rounds haven't been seen since.

A week later and 170 miles south, a trailer loaded with $70,000 worth of cheddar and other cheeses was stolen during the wee hours of the morning from a distribution center in the village of Germantown.

Germantown cops quickly reported the missing cheese on the department's Facebook page, and hours later the trailer was spotted about 25 miles away in the Milwaukee area. Drat, the cheese was all gone.

Detectives tracked down some of the cheese within hours and recovered what they believe to be the rest in a separate location on Saturday, said Germantown Lt. James Theep.

"We just don't know who" is behind it, he said. Investigators also don't know whether the Germantown cheese crooks pilfered the Parmesan in Marshfield a week earlier.

"We're looking at all possibilities," said Marshfield Police Lt. Darren Larson.

Larson said his detectives have not located the trailer, tractor or purloined Parmesan that was produced in LeSueur, Minn., and was supposed to end up in Elgin, Ill.

"I've been a police officer for 28 years … and this is unusual," Larson said. Sure the cops have been called after someone has lifted a pound or two of cheddar or maybe a few mozzarella sticks but never a truckload of cheese.

"It's a first for us," Larson said.

He said it's unclear who the man was behind the wheel of the semi that pulled up to the Wow Logistics distribution center in Marshfield on Jan. 14 and drove off with 1,000, 40-pound blocks of Parmesan.

Investigators are trying to untangle exactly how a truck pulled in and drove away with that much cheese, Larson said.

The question at first was whether it was a clerical error or theft, he said. "But as time goes on … it becomes suspect."

Tracking down the getaway vehicle has been tough because it was a nondescript, white refrigerator trailer with a nondescript white semi-tractor, Larson said. "So it really gives us little to go on."

What Larson does know is that if the seal on the trailer unit is broken, the cheese can't be legitimately sold.

"I'm not aware of a black market for cheese," he said. "But it's not inconceivable, because essentially everything that can't be marketed on the legitimate market certainly has a place on a more criminal one."

Larson doesn't know what the street value would be.

In Germantown, the fromage heist occurred about 2:15 a.m. Friday when a semi loaded with a variety of Crystal Farms cheese products — from cheddar to cream cheese — went missing, Theep said. Within hours, the tractor and trailer were found in separate locations. Detectives hot on the trail discovered a pile of cheese in one building and what they presume is the rest of the load was found the next day in another building.

Theep is mum on some of the details because it's an open investigation. And he's doing his best not to crack amid a swirl of cheese puns flung his way.

"This is definitely something out of the ordinary, for sure," he said. "It's a lot of cheddar."

Mary Lynn Smith • 612-673-4788