Family and friends of a Winnipeg-based soldier were preparing for the worst Saturday. Mark Salesse was in the midst of a military training exercise in Banff National Park when an avalanche hit.

It happened while members of the 435 Transport and Rescue Squadron were climbing on the Columbia Icefield in Alberta Thursday.

On Saturday, Parks Canada said efforts to locate Salesse are now a 'recovery mission.'

Searchers are still looking in Banff National Park for the 44-year-old, a Royal Canadian Air Force member based at 17 Wing in Winnipeg.

The experienced search and rescue technician was leading three other soldiers down the "Polar Circus” ice climb when an avalanche hit.

Salesse’s mother, Liz Quinn, knew something was wrong when two soldiers knocked on her door in Moncton.

"I knew it wasn't going to be good news," she said during a phone interview.

Liz Quinn she says her son lived his life doing what he loved. "Mark was a gentle person, thoughtful, kind."

The Department Of National Defence says conditions were clear when the climb started, but later deteriorated.

Military officials told Quinn Saturday they believe Salesse fell 800 feet (244 metres) before snow from one or more avalanches fell on top of him. Since then, search crews have been held up because the risk of another avalanche is too high.

In an email Saturday, Parks Canada said visitor safety staff are waiting for improved weather conditions in order to mitigate the avalanche risk by doing explosive control. Once it is deemed safe, specialists will access the site to conduct a ground search.

Safety specialists from Parks Canada are working with dog teams and air support to search for the climber in the area of the Polar Circus Ice Climbing route. On Friday morning, specialists searched the area by helicopter. The area of the avalanche was located and there were no visible signs of the missing climber.

At Winnipeg's 17 Wing, the base says everyone is in shock, whether they knew mark or not.

"This is one of their own. This is one of their friends, one of their colleagues, somebody they work with side by side," said Capt. Bettina Mcculloch-Drake.

Salesse is well known at the St. Boniface ice wall. The president of the club said Salesse came here about once a week to practice his climbing.

"He was here a couple of weeks ago before going the Rockies," said André Mahé.

Mahésaid Salesse is a strong climber and has survived serious falls before.

Salesse was badly injured in another training mishap four years ago, according to a 2011 military news release. He suffered injuries to his lower back, ribs, leg and pelvis after falling from an ice wall near Ouray, Colorado.

Knowing that, Mahé said he won't talk about his friend in the past-tense."He is a fantastic guy and we hope he will be back here to do some climbing," he said.

One Winnipeg climber who met Salesse a few times said the Polar Circus ice climb is long and challenging.

"It forms in kind of the cleft of the cliff, and if there's an avalanche it's tough to get out of the way," said Jamie Knight.

He attempted to climb the same route as Salesse on six different occasions, and only completed it about two weeks ago.

Knight said he's staying positive and hoping for the best.

Officials said the search area is relatively small, but the geography, weather and snow cover make for a complex search.

Canmore-based ice climber Brent Peters said above-freezing temperatures on Saturday have loosened the packed snow in the area, increasing the chance that rescuers might trigger an avalanche.

Friends and colleagues posted Twitter messages expressing concern and support for the missing climber:

Mark is a former and highly valued member of CVGSAR who never forgot his team, always dropped in to check on us... http://t.co/NPJ94EJVE1 — Comox Valley SAR (@ComoxValleySAR) February 7, 2015

Former member of my Regiment BCR(DCO).If anyone can survive its Mark. One of the toughest soldier I have served with. http://t.co/WjcKWnKOjk — Harjit Sajjan (@HarjitSajjan) February 7, 2015

Parks Canada Banff, Yoho, Kootenay and Jasper Visitor Safety Specialists and a Parks Canada Warden Dog Handler are all involved in the operation.

- with a report by Michelle Gerwing and files from CTV Calgaryand The Canadian Press