The search for a St. Louis Park father and son who went missing in a vast Colorado wilderness area intensified Tuesday, with more than twice the number of searchers scouring an area where cellphone signals from the pair were detected on the day they set off on a hike from Echo Lake.

About 50 people from seven Colorado search and rescue teams fanned through the wilderness on skis, snowshoes and snowmobiles in search of Damian McManus, 51, and his 18-year-old son, Evan, who haven’t been heard from since last Wednesday.

Rescuers have been hampered in their search because they had no clear indication as to where the two were headed or whether they were equipped for winter travel. Also, no one knew the two were missing until five days after they started their hike.

The first two days of the search were hampered by harsh weather. But on Tuesday, the winds were calm, temperatures were in the 30s and skies were clear, allowing a helicopter to help, said Howard Paul, a rescue effort spokesman.

Signals from the cellphones to a cell tower also have helped to narrow the search, although it still covers several square miles, Paul said.

The search is expected to resume Wednesday.

Mary Lynn Smith and Paul Walsh