The River by Cheryl Kaye Tardif

A "mile-a-minute pot-boiler myster[y]", raves Edmonton Sun columnist Graham Hicks.
Take the ride of your life as Del and a motley group of strangers set off for the Nahanni River--the Bermuda Triangle of Canada--in search of her father. What Del finds is a deadly conspiracy that threatens not only their lives, but all of humanity.