Law officers said Thursday they've dented a major marijuana operation in Montana, as they arrested five people in Great Falls and Helena and seized 135 pounds of the drug near Missoula.

Authorities said the marijuana was discovered earlier this week when Utah Highway Patrol officers arrested an alleged delivery man and that the drug apparently was destined for Great Falls."We've been working on this thing for a long time," Cascade County Sheriff Barry Michelotti said.

Four men were arrested Thursday in Great Falls on drug charges; a fifth man was arrested in Helena; and a Frenchtown couple was arrested at home Wednesday night.

Missoula County sheriff's detective Larry Jacobs said the primary busts were supposed to take place in Great Falls and work back to John and Catherine Webb of Frenchtown, but the chance arrest of the delivery man in Utah changed the plan.

Jacobs said Utah officers stopped a man near Moab, Utah, and smelled marijuana in the car. Officers then found 135 pounds of the drug packed in four suitcases. The driver, from the Phoenix area, was arrested and then told authorities the pot was headed for Missoula County, Jacobs said.

Utah officers flew the would-be delivery man to Missoula, where investigators questioned him. Accompanied by a dozen officers, he delivered the drugs the home of John and Catherine Webb, near Frenchtown, Jacobs said.