John McCluskey, 45, Tracy Province, 42, and Casslyn Welch, 44, have been sought since the two men escaped from an Arizona prison on July 30. Province was recaptured Monday. (RCMP)

Authorities say they have captured one of two American prison escapees who Mounties feared might have been headed to Canada.

The U.S. Marshals Service said Tracy Province, 42, was arrested early Monday in northwest Wyoming, about 100 kilometres outside of Yellowstone National Park. He was armed with a handgun, the service said.

Another inmate — John McCluskey, 45 — and a suspected accomplice — Casslyn Welch, 44 — were still on the lam.

Police said they are considered armed and dangerous, and are telling anyone who recognizes them to call 911.

In Vancouver, the Mounties had issued a warning on the trio Sunday, saying they might have been headed to B.C.

The U.S. Marshals Service said the men are persons of interest in a double homicide after their escape from an Arizona prison on July 30.

Earlier this week, forensic evidence linked at least one of the inmates to the killings of an Oklahoma couple in New Mexico.