The girl was injured last Thursday when she crashed into a fence. She was rushed to hospital in Winnipeg and taken off life support this week.
"Oh we're devastated, our family is devastated, our Holiday Mountain team is devastated," said Bernice Later, general manager at Holiday Mountain Resort.
"We work very hard to provide a safe environment and in 55 years we've never had a fatality, so we're just shocked."
The girl, who was from Thomas Greenway Middle School in Crystal City in the Prairie Spirit School Division, had just completed the beginner training on the hill. She was on a free ski with friends when she mistakenly went on an expert run, Later said.
"Just tragic. It looks like she just lost control, going too fast," Later said.
Prairie Spirit School Division Superintendent Keith Murray says school staff and a divisional crisis support team have been at the school to help students deal with the tragedy.
The resort is located in La Rivière, about 160 kilometres southwest of Winnipeg.