MINNEAPOLIS — A team of firefighters from the Minneapolis area is heading to the Colorado mountains this week to search for any sign of two hikers from Minnesota, a father and son, who have been missing since April.

Damian McManus, 51, and his son, Evan McManus, 18, both of St. Louis Park, were last heard from April 2 when they went to Mount Evans for a spring break hike. Authorities found their car in the parking lot at the base of the mountain. Snowy conditions on the rugged terrain made the search dangerous, and rescue teams called off the search. Another search was mounted in May. It included parties from across Colorado, but also turned up nothing.

“You know, as more and more time goes by and they’re not found, it’s just devastating,” family spokeswoman Andrea Bouzrara said. “The process of grieving and moving forward is just so hard.”

Bouzrara said four firefighters from St. Louis Park, Edina and Eden Prairie have volunteered to go. They’ll help comb the mountain Tuesday, Wednesday and Thursday in hopes of recovering the remains of the father and son.

The volunteers include Hugo Searle, a St. Louis Park firefighter and high-altitude mountain guide who has scaled Mt. Everest.

“I live in St. Louis Park, my wife is a teacher in the school district, and my daughter goes to the same school that Evan used to go to,” he said. “So we have felt very connected to this tragedy right from the start.”

Bouzrara said volunteers have been making weekly trips to the mountain all summer, logging more than 4,500 hours of searches.

“They have narrowed the area down somewhat, although … they’re still not 100 percent sure that they’re even in the right place,” she said.

The firefighters are taking personal time to make the trip. A donor is picking up the airfare. The time for finding the McManuses is short.

“They basically have a five-week window,” Bouzrara said. “And then it will start to snow again.”