The search for a missing bow-hunter from Kalispell has intensified in the Big Hole Battlefield National Park after Robert Carter, 53, failed to respond to his wife and family for over a week.

Beaverhead County Undersheriff David Chase said the search for Carter has now been concentrated in one 40 square mile area not far from Wisdom.

"The area is full of heavy deadfall and timber at an elevation of 7,700 feet," Chase said. "Temperatures at night are dipping down into the low 20's, while daytime highs are in the 70's."

Chase described the assets in place to help find the missing hunter.

"We have air support, dog teams in the area, ground teams of hikers and all-terrain vehicles as well as horses," said Chase. "We've concluded extensive interviews with any hunters and campers to try to determine a timeline of activity for the lost hunter."

photo from NBC Montana

Since Carter has not been heard from since last Wednesday, Chase said the search has intensified, in case he may have been injured, and the fact that he was wearing camouflage clothing complicates the search.

"Hunters that are lost during rifle season normally have hunter's orange and are much easier to find, however, bow-hunters wear camo to get closer to their game, so if they get lost or injured, it's so much more difficult to spot them."

West specifically wanted to remind KGVO listeners who hunt alone to take certain precautions in case they become lost or injured.

"He had his vehicle parked at a trailhead, and if he had just left an itinerary inside the vehicle of where he was headed, it would be so much easier to find him," Chase continued. "They sell these little portable units called a 'spot' that when actified, can send out a GPS signal that can lead rescuers to your location."

Chase would not say how much longer the effort would continue to locate Carter, but that all search teams are working as long as they have daylight.