Skiers have triggered an avalanche near Wanaka.

The group of four were in an "out-of-bounds" area in the Hidden Valley area of Treble Cone about 12.30pm when the avalanche was triggered but they managed to ski out safely.

"Before doing so they checked the debris and carried out a transceiver sweep of the site which did not reveal any signals," a spokesman said.

"The group also searched for visual tracks and any further clues outside of the area and the full length of the debris, and did not find any evidence of other individuals or groups in the area at the time."

The spokesman said the avalanche was a "size 2", on a scale of five, five being the largest.

It was up to half a metre deep in open terrain.

A member of the public who saw the party searching debris alerted mountain workers.

Treble Cone initiated its search and rescue procedures and informed Wanaka police.

A helicopter, Treble Cone patrollers and two search dogs with handlers are in the area to search the debris.