Before Province's capture, the group had been sighted in Yellowstone National Park over the weekend. Gonzalez said Monday that McCluskey and Welch are no longer in Yellowstone National Park but are in the vicinity.
Rivera said today officials believe the couple to be in Montana but have been fielding tips and following investigations from Canada to Florida.
ABC News consultant Brad Garrett said that each day McCluskey and Welch remain on the lam makes it harder for them to keep their cover.
"It's very difficult to remain on the lam because keep in mind everyone virtually knows what they look like at this point," Garrett said. "In my mind, it's clearly only a matter of time that they eventually will get caught."
Gonzalez doesn't rule out that friends or allies from the white supremacist network might be helping the couple.
"There are some enclaves in that part of the country and they have connections and friends in that area they might be headed to," he said Monday.
There are more than a dozen extremist groups with links to white supremacists in Montana, Wyoming and Idaho, according to the Southern Poverty Law Center website.
Gonzalez said Province and McCluskey are suspects in the double-murder of a husband and wife who were burned in their trailer in New Mexico last week. The charred remains of Linda and Gary Haas were found last week after a rancher came across their wandering dogs. The couple's truck was found 120 miles away in Albuquerque with evidence connected to the escapees, police said.
McCluskey's mother is now under arrest for allegedly giving McCluskey and Welch clothing, money and a getaway car.
McCluskey's stepfather, Jack Washburn, expressed his anguish at the pain his stepson has caused.
"He'll never realize how bad he's hurt me and his mother," Washburn said.
CLICK HERE to see a picture of each of the runaways at the U.S. Marshal website.
The Associated Press contributed to this report.