MONTEZUMA CREEK, Utah – Navajo tribal police said Friday they were closing in on a pair of fugitive survivalists who have eluded a massive manhunt since the killing of a Colorado policeman nearly six weeks ago.

"Today we will end it," said Navajo Tribal Police Chief Leonard Butler.

The cat-and-mouse hunt for the fugitives along the brush-choked banks of the San Juan River in southeastern Utah intensified once again after two men were spotted Thursday evening crossing a clearing about six miles west of this town on the northern edge of the Navajo Indian Reservation.

The two were believed to be fugitives Alan "Monte" Pilon, 30, of Dove Creek, Colo., and Jason McVean, 26, of Durango.

"When they were spotted yesterday they were running along a clear area, something like a road," Butler said Friday. "It appeared to the officer observing they didn’t have any long guns in their hands."

Butler said the two men, if they were the suspects, may still have sidearms.

From the clearing, officers tracked a set a footprints to the San Juan River, where one of the fugitives is believed to have floated downstream to a small island about eight miles west of Montezuma Creek.

Law officers planned to sweep the island. Butler said no tracks of the second man were found.

Pilon and McVean, along with Robert Matthew Mason, 26, of Durango, are wanted in the May 29 shooting of Cortez police officer Dale Claxton after he stopped three men in a stolen water truck. Police say the trio wounded two Colorado sheriff’s deputies in a running gun battle, fired at a National Park Service employee in Hovenweep and then disappeared on foot into the desert canyon country.

Mason was found dead of a self-inflicted gunshot wound on June 4 near Bluff – hours after he shot and wounded San Juan County sheriff’s Deputy Kelly Bradford.

Pilon and McVean have eluded detection since, despite one of the largest manhunts ever in the Four Corners area. At its peak, the search in the arid wastes along the Colorado-Utah border involved more than 500 law officers who fanned out on foot, helicopter, horse, plane and four-wheel-drive vehicle.

Authorities established roadblocks and brought in the FBI, National Guard and search dogs. The search was scaled back considerably, then intensified again June 28 when a 9-year-old girl spotted two men trying to get into a water truck parked in the backyard of her uncle’s home in Montezuma Creek.

The 12-mile-long corridor from Bluff to Montezuma Creek has been the focal point of search efforts since. Last week, fires were set in a river bed to burn off thick vegetation that had shielded caves and other potential hiding places. But after that effort failed to turn up the fugitives, San Juan County turned the search over to the federal government.

On Tuesday night, officers saw what appeared to be a campfire burning along the river bank, Butler said. SWAT teams set up observation points around the area and waited until Wednesday morning to begin searching.

Sometime during the night Wednesday the two men apparently crossed the river and broke the police containment, again eluding officers until they spooked some livestock grazing in the brush.

Navajo Nation officers again set up observation posts Thursday afternoon, at which point the officer saw the two men crossing the road.

The fugitives are wanted on three federal warrants, including unlawful flight to avoid prosecution, assault on a federal officer and federal carjacking. The manhunt began 43 miles to the east in Cortez when three men fatally shot officer Claxton and fired more than 500 rounds at pursuing officers – wounding the two Montezuma County sheriff’s deputies.