The Joint Rescue and Coordination Center in Victoria were alerted to the crash just after 9:00 a.m., the Canadian Broadcasting Corp. reported.
The helicopter's beacon, which is designed to go off automatically during a crash, reported the site just west of Terrace, on the back side of Sleeping Beauty Mountain.
A Buffalo aircraft and a Cormorant helicopter, along with ground crews, were sent to the scene, but have been unable to reach the wreckage due to bad weather conditions and the threat of avalanche, officials said.
Bailey Helicopters, owner of the crashed helicopter, reported all three men aboard the helicopter were killed.
Peter Schweiler, spokesman for Bailey Helicopters, said the men were aboard the helicopter for a training flight.