Nikita and Kelsey McAlpine died when their wagon collided with a ute on the Omeo Highway, east of Mount Hotham, about 5pm on Sunday.

The township's 500-odd residents have been left gutted by the deaths.

Tributes flowed on social media on Monday, remembering the "beautiful girls" from "one of the closest families you'll ever meet".

Omeo's Golden Age Hotel, where both girls worked, said staff were devastated by the news.

"RIP Nikita and Kelsey, two beautiful girls taken way too soon," a post on the hotel's Facebook page said.

A GoFundMe page set up to raise money for the sisters' family raised almost $14,000 of its $20,000 goal in 11 hours.

"If you know this family, you will know how close they all were and how beautiful these girls were," the campaign's organiser and close family friend, Jessie Symons, wrote.

"For the people who don't, these two amazing girls were beautiful. At 18 years old and 15 years old, these girls had so much more of their lives to live, so many dreams to chase after.

"They had hearts of gold ... very well mannered and loved by all in this community.

"These two beautiful souls will never be forgotten by the hearts they have touched."

Nikita, 18, was a student at Charles Sturt University.

The driver of the ute, believed to be a man in his 60s, was taken to hospital in a critical condition.

The cause of the crash is yet to be determined. Police have called for any witnesses to call Crime Stoppers on 1800 333 000.

The sisters' deaths bring the state's annual road toll to 186, compared to 214 at this stage in 2016.