'You want me to do what?' my friend asks, before disappearing quicker than an ice block in the Sahara. She was saying no to an opportunity to make like a modern-day Tarzan.
Instead of vines, there are five steel cables suspended between two mountains some 12 storeys above a raging glacial creek. Ziptrek Ecotours is responsible for this adrenalin-rush experience. It's elevated the concept of the guided forest tour and become the hottest all-weather tourist attraction at the Canadian ski resort of Whistler.
The first thing we're asked to do when we book for the two-and-a-half hour Ziptrek tour is sign a liability waver. The feeling of risk this generates is probably disproportionate to the actual danger, given that two years of environmental assessment and planning preceded construction of the facilities.
'We wanted the adventure component and also a level of comfort,' says Dave Udow, who set up and runs Ziptrek. 'An accident is not an option.'
After signing away our rights we're fitted with climbing harnesses. These will connect us to a pulley on a steel cable along which we'll zip at speeds of up to 80km/h. After a dummy run on a practice line, we're taken to our launching pad: Blackcomb Mountain, where the 2010 Olympic ski jump will be built.
We take turns quaking at the edge of our 'where eagles dare' platform, awaiting the shove that will send us on a flight path from Blackcomb, over the white waters of Fitzsimmon Creek far below and on to Whistler Mountain.