The group of around five so-called "freemen", wanted on state and federal criminal charges, have set up their own "supreme court" at their makeshift headquarters near the small town of Roundup, and have issued a "citizen's declaration of war" against government officials.
Federal law enforcement authorities are reluctant to take action. Apparently they want to avoid a repetition of the debacle at Waco, Texas, or a stand- off that ends in bloodshed.
Government officials are aware that America's far right made a martyr of Randy Weaver, after federal agents laid siege to his mountain hide- out in Idaho in 1992 in a bungled military-style operation that led to the death of Weaver's wife and son.
Seven weeks ago, the local county prosecutor wrote to President Bill Clinton asking for federal assistance.
He described the freemen's ring-leaders as dangerous "terrorists", and warned the President of the rise of violent right-wing anti-government groups in America's west and mid-west.
The letter was dispatched before the bombing of a federal building in Oklahoma, in which 168 people died.
But the prosecutor's staff say the President's office did not reply, indicating that the US government wishes to avoid a confrontation with militia-style groups. The fugitives are wanted for an array of charges, including threatening and impersonating police officers, tax evasion and violating gun laws.
The prosecutor, John Bohlman, of Musselshell County, who has taken to wearing a bulletproof vest after receiving threats from the men, says they are "extremely well-armed". Supplies of food, money and weaponry, including assault rifles and more than 1,000 ammunition rounds, are stashed away in their cabin, a building which tax authorities have seized for non-payment of taxes but have yet to occupy.
Federal agents are anxious to avoid a stand-off,owing to the risk that their own officers could be killed. Their hands-off approach has prompted complaints that they are encouraging far-right extremists to act in brazenly criminal manner.
There are suggestions that the federal authorities are refusing to pursue charges in order to avoid conflicts. "They could easily have charged this men with more federal offences," said a Musselshell official. When local police visited them, in the hope of making arrests, they were sent packing with blood-thirsty threats.
Similar incidents have prompted officials to complain of an outbreak of "Weaver-fever" in Montana. Three hundred miles away in the Bitterroot Valley, Calvin Greenup, the 52-year-old leader of a paramilitary anti- government group, has been holed up in his ranch for about a month, vowing to "go down shooting" if anyone attempts to arrest him.
Mr Greenup faces several state charges, including harbouring his two sons, who are also wanted men. So far officials have only managed to impound his animals - 10 elk - but have refrained from seizing him. "We will get him, but it will be at my pace," the local sheriff, Jay Printz, said.l "I don't think its worth getting anyone killed - including him."
Sheriff Printz scoffs at Mr Greenup's threats, such as: "If he gets me, he had better get me good, because I'm going to bite back." Not everyone takes him so lightly. In his letter to Mr Clinton, Mr Bohlman pointed out that when a National Guard helicopter strayed over Mr Greenup's property, the self-style militiaman summoned his followers who began to prepare to shoot down the aircraft.
In a third incident in Montana, US marshals have reportedly failed to make any move against a man in a cabin in Missoula who allegedly shot a police officer more than a year ago - an offence that would normally attract the full force of official wrath.
"We are acting with the utmost caution in these situations," said Randy Little, an agent with the Bureau of Alcohol, Tobacco, and Firearms in eastern Montana, "We don't want to see a repeat of past mistakes."