Dave Hannagan, 46, and his American companion Cathy Grimes, 36, had shared their excitement on social media after meeting on a new year ski holiday across the US.

The pair clicked instantly and travelled though Aspen, Telluride, Texas and Oregon's Mt Bachelor, before reaching Jackson Hole Mountain Resort, a popular ski spot in Wyoming.

"Big Wave Dave, you're the best date ever! Ready for Jackson Hole?!" Ms Grimes posted on Facebook on Friday.

Just after 2pm on Sunday US time, an avalanche was triggered in a popular but hazardous out-of-bounds area of the resort, local media reported.

Mr Hannagan and Ms Grimes died while a companion, a male skier, survived after grabbing onto a tree to avoid being swept off a steep cliff face.

Local website buckrail.com reported that the avalanche was skier-triggered and between one to two metres deep at the crown. It broke on a steep face that had been loaded by wind and new snow, Teton Gravity reported.

Local rescue were quick on the scene and pulled Mr Hannagan and Ms Grimes out of deep snow about 3.20pm however both were pronounced dead.

None of the group were wearing avalanche transceivers or had a good knowledge of the area, Jackson Hole Mountain Resort spokeswoman Anna Cole told Jackson Hole News & Guide.

"It's upsetting because these folks... we don't think they we're properly prepared for the backcountry," Cole said.

Mr Hannagan was an agent at Raine & Horne Double Bay/Bondi Beach and a senior instructor at Let's Go Surfing, where he was known around Bondi as "Big Wave Dave".

On the real estate company's website, he said he was a Level 2 Ski Instructor and had previously worked at Perisher.

His online profile said his two loves in life were skiing and surfing and his motto was "do what you love, love what you do and also be good at it".

Close friend and boss Ric Serrao said he was "a bit of an icon" around Bondi.

"He was just one of those real true blue people, he was just so genuine," he said.

"He loved to travel, he loved to surf, at work he was one of our secret smoking guns, we called him the deadly weapon because he had this smile and people just loved to work with him."

Mr Serrao said Mr Hannagan had met Ms Grimes while travelling this month and they "instantly clicked".

"He's had the best year of his career, he'd just met a girl over there that he thought was going to be the one and then this happened. We're all in disbelief."

Mr Hannagan met up with his siblings Paula and Andy in Oregon on January 16. The pair both posted tributes to Mr Hannagan on Facebook on Tuesday.

"Love my brother," Paula Hannagan posted on Facebook.

Friends of Ms Grimes, who is from Arizona, mourned the loss of a "bright shining light".

"Today marks a very sad day as the world lost the bright shining light," a friend, Nick Duckro, posted online. "You will forever be missed doll face, the group won't be the same, but I know you'll check in with us from time to time."

Mike Rheam, a forecaster for the Bridger-Teton Avalanche Center, said the group skied into an area, crossed by a cliff band, that is known as hazardous to local skiers.

"We've had fatalities in this area in the past," Rheam told the Jackson Hole News & Guide.

"People who aren't familiar with the terrain... it gets steeper and the avalanche breaks over them... they were carried over the cliff."

A DFAT spokesman said they were "providing consular assistance to the family of an Australian man who died in the United States, in line with the Consular Services Charter. For privacy reasons, we will not be providing further information."