The Stadium Express chairlift, built for the 2011-12 season, is the newest of several lifts that rise from the Mount Hood Meadows day lodge. The diverse terrain at Meadows ranges from easy novice slopes to expert chutes in the restricted-access Heather and Clark canyons.

Heidi Rather was sliding head first, with no way to stop, down an icy slope.

She’d gone to Mt. Hood Meadows on Sunday to watch her son’s skiing competition and was taking a few runs with her daughter around 10:15 a.m. when she headed toward Heather Canyon, an area of the resort known for steep grades and challenging terrain.

Rather is an expert on the mountain. The 56-year-old retired nurse has been on helicopter ski trips and is a regular at Mount Bachelor near her home in Bend. When she passed through the gates to Heather Canyon, which ski patrollers periodically open and close depending on conditions in the area, she was looking forward to what she thought would be an “epic powder run.”

That’s not what she found.

After a brief traverse to her left, she went to take her first turn and the edge of her skis immediately slid out from under her on an area of ice, invisible and frozen solid. She fell and accelerated down the slope on her chest, headed straight for a tree.

“I thought to myself, ‘oh my god, I’m going to die,’” Rather said.

Fortunately for Rather, most of the impact was absorbed by her chest. If she had been at a slightly different angle, she said, she might have hit the tree head first. Still, she was in a great deal of pain and wasn’t exactly sure how badly she was hurt.

A ski patroller was nearby, Rather said, and immediately came to her aid. Within a few minutes, another person came sliding down the hill, knocking the patroller off balance and sending her backpack down the hill, which she had to go and retrieve. When the patroller came back to assess Rather, it was clear she couldn’t make it off the mountain on her own and the patroller called for a sled to ferry her down to the medical clinic at the base of the resort.

It took nearly an hour and, as Rather waited for help, she could hear multiple calls on the patroller’s radio about other injured skiers. At one point she heard the patrollers calling for a Life Flight helicopter. She knew someone had been injured much worse than she had.

That person was Ryan Zeitner, a 45-year-old Portland man who fell on the same slope while riding with his friend, Colby Hunt.

Similar to Rather, Hunt and Zeitner were expert snowboarders, each with 30 years of experience on the mountain. Hunt had worked at Mt. Hood Meadows in the early ’90s and knew the mountain well. He had ridden Heather Canyon, and the area they dropped into known as Moon Bowl, “countless times,” he said. But he’d never encountered conditions like he saw on Sunday morning.

“We entered Moon Bowl gate and traversed right towards an area of open, small trees that funnels into a gulley. As soon as I dropped in I slid out on the hardest smoothest ice sheet I’ve ever encountered,” Hunt said in an email. “It was a huge, bullet-proof, invisible ice sheet.”

Zeitner fell too, sliding down the mountain until he was stopped by two ski patrollers at the bottom of the slope. He was wearing a helmet, but Zeitner was badly injured. As Hunt and the patrollers did their best to care for Zeitner, other skiers and snowboarders were sliding down the hill around them and Hunt took a position uphill from his friend to try to protect him. He saw one snowboarder slide past them and hit a tree, the impact knocking the rider out of his bindings, sending his snowboard flying. It looked to Hunt like the snowboarder was injured.

Despite the efforts of Hunt, the ski patrollers and a doctor who happened to be in the area, Zeitner died of his injuries on the mountain. He was the second person to die in the canyon over the weekend. Tim Bauters, a 47-year-old engineer from California, went missing while riding on Friday. His body was found in a gully Monday evening and medical examiners have yet to determine how he died.

Heather Canyon, located on the east side of the resort, features some of Meadows’ most rugged terrain, sought after by advanced skiers and snowboarders.

It’s home to steep slopes, wide-open bowls and tight trees and gullies that can be accessed through gates that are open or closed, depending on daily conditions. Those gates allow access to the canyon from the ridegeline above to runs with names like “A-zone,” “Twilight bowl” and “Moon Bowl,” where both Zeitner and Rather fell on the ice. All areas of Heather Canyon are considered “extremely difficult” double black diamond terrain.

Meadows’ trail map warns that Heather Canyon and two other areas of the resort — Clark Canyon and Private Reserve — aren’t patrolled on a regular basis and have avalanche danger at all times. Skiers in those areas should also be aware of waterfalls, creek holes and unmarked obstacles in those areas, the map warns.

Every morning, ski patrollers inspect the canyon, said Greg Pack, general manager at the resort. They consider whether the snow is prone to avalanches and if it’s safe for the public to ride. They take into account temperature changes and weather. They also ride the runs themselves.

Pack said the snow in Heather Canyon on the day Zeitner died was “packed powder with variable conditions.” It was Sunday of Presidents’ Day Weekend and the resort was busy, with roughly 1,700 people riding the lift from the bottom of the canyon. While there were several injuries, Pack said there was not a noticeable uptick from any other busy weekend.

But Pack stressed that ski patrollers don’t consider crowds when they decide whether to open the canyon to the public. If Heather Canyon isn’t safe, he said, they keep it closed, often to the displeasure of expert skiers and snowboarders who flock to that part of the mountain.

“We don’t open things unless we feel totally confident that they are safe,” Pack said. “We’re extremely cautious. We have family members and kids who ride the mountain, and we think about that when we open stuff. We always prioritize safety.”

Pack said the resort didn’t have any plans to change how it assesses which areas to open or close to the public, but he said the resort would be doing a full investigation into the deaths of Zeitner and Bauters and would be sharing their findings with both the U.S. Forest Service, which owns the land where the resort is located, and the sheriff’s office.