Law enforcement officials arrested three men Thursday and are looking for a fourth in connection to an armed home invasion robbery that occurred Wednesday afternoon in the Happy Valley area.

Flathead County Sheriff Chuck Curry said the investigation has uncovered a heroin trafficking and money counterfeiting operation with roots in Columbia Falls and Whitefish.

Deputies executed search warrants in both cities Thursday and arrested 25-year-old Bradley Thompson and 29-year-old Kevin Gaethle, both of Kalispell, as well as 22-year-old Columbia Falls resident Kelly Campbell.

Investigators are still looking for 27-year-old Stephen Acton. The Whitefish man should be considered armed and dangerous, Curry said. He’s described as being 5 feet 11 inches tall, about 220 pounds, with brown hair and blue eyes.

Numerous firearms were seized from his residence as the Sheriff’s Office served a search warrant Thursday.

The robbery occurred Wednesday at about 3:30 p.m. when two armed men entered the home, held a 16-year-old girl at gunpoint and stole a safe containing firearms, ammunition and other items. It’s unclear if anyone else was home at the time.

The men reportedly loaded the safe into a passenger car and fled the area after the robbery.

Most of the belongings were recovered Thursday as numerous search warrants were executed in Whitefish and Columbia Falls, Curry said.

Sheriff’s Office personnel also confiscated heroin and materials that are believed to have been used in a counterfeit currency operation, he said.

“It’s our belief certainly that the suspects were, or at least some of this group were, going to travel most likely to the Portland area to replenish their supply” of heroin, Curry said.

The Kalispell Police Department came up with a big lead in the investigation Thursday morning after responding to a report of a shoplifter at a business on Hutton Ranch Road.

Curry said the man was driving the same rented car described by witnesses. Investigators were able to develop further leads from there, he said, leading to the search warrants and seizure of property and narcotics.

“It’s a cliché, but I have to say that a lot of it was just very good police work,” Curry said.

It’s still not clear what, if any, relation the suspects had to the victim of the robbery.

“It appears that one of the bad guys, or suspects, was in the house at some point in time prior,” Curry said.

So far, Thompson has been charged with robbery, theft, obstructing a peace officer and resisting arrest. Gaethle is charged with a parole violation, robbery and criminal contempt, while Campbell is facing charges of robbery, possession of stolen property and a parole violation.

Curry said all three will likely face drug charges as well. The investigation is still under way, he said, and additional arrests are expected.

“There may even be more charges to tack on as well,” he said.

The alleged counterfeiting operation will be investigated by federal authorities, Curry said.