Bear Island

An announcement at the end of the closing credits reads "Coming Soon -Alistair MacLean's Goodbye California". This movie was intended as the first in a series of Alistair MacLean adaptations, which would have included "El Dorado", "Athabasca", "Night Without End", and "The Way to Dusty Death". The next intended movie in the series, "Goodbye, California", was to be shot with a budget of between $12-$13 million. However, due to this movie's disappointing box-office performance, "Goodbye, California", and the other titles were never made by producer Peter Snell, who had bought the rights to numerous MacLean works in 1975, including ones at the time that had not even been published or written yet. Snell, however, did get The Hostage Tower (1980) and Detonator II: Night Watch (1995) made for television.

Snow vehicles seen in this movie included Swedish Larven "Caterpillar" snow scooters and amphibious aircraft-propelled catamarans, known as hydrocopters. Of the latter, producer Peter Snell said, "There are only 80 of these built so far, and we are introducing them to general audiences. It's our toy, our version of the road chase through the streets of San Francisco for Bullitt (1968)."

During production, director Don Sharp and four crew members got trapped and stranded on a glacier in a sudden blizzard whiteout during a location scouting trip. According to the 3/11/79 edition of "The Los Angeles Times", the five men were left without sufficient food and warm clothing until a search and rescue squad found them three days later.

This movie was the most expensive movie ever made in Canada at the time, according to the book "The Hollywood Hall of Shame" by Harry Medved and Michael Medved.

Christopher Lee co-starred in this Alistair MacLean adaptation after having been fired by Richard Harris from the Alistair MacLean film Golden Rendezvous (1977).