With little to go on in their hunt for a missing Texas man, rangers at Rocky Mountain National Park are beginning to scale back their search efforts.

The search in the park has been ongoing since Troy Green, 39, of San Antonio, was reported missing and his rental car was found Friday at the Bear Lake parking area in the park. But after a third day of extensive searching, both on the ground and from the air, and with the help from hundreds of park visitors who came to the Bear Lake area for snowshoeing, skiing and sledding, the decision was made Monday to begin scaling back the mission.

"The saturation of this area by searchers, dog teams, a helicopter, and large numbers of recreational users provided a great deal of coverage but again with no clues," park spokeswoman Kyle Patterson said in a release. "Search teams on Sunday encountered deep snow and pockets of considerable avalanche conditions. The depth of snow since Thursday has hampered search operations. Aerial searching detected several large slab avalanches on the northeast aspects of peaks along the (Continental) Divide but with no evidence that they were human triggered."

In the coming days, a small team of rangers will focus its search on pockets of challenging terrain in the Bear Lake and lower Tyndall Gorge areas, the spokeswoman said.

The investigation is ongoing. If anyone was visiting the Bear Lake area on Thursday or Friday, park rangers would like to hear from you. Please call Rocky Mountain National Park at (970) 586-1204.

Mr. Green was planning to attend a conference in Denver. When his wife did not hear from him on Thursday, she contacted the Denver Police Department. He did not arrive at the conference on Friday.

Two park visitors told rangers they spoke with the man at 1 p.m. on Thursday at the Bear Lake Trailhead, but they did not see what direction he went from there. Between witness reports and park rangers’ investigation, it is known that Mr. Green purchased additional gear after he arrived in Colorado, park officials said. It is possible that he was wearing black snow pants, a black puffy down jacket, black gloves and a black balaclava. He also was seen wearing hiking boots and a royal blue and grey Camelback hydration pack.