PHOTOS: THE DAVID THOMPSON BRIGADE; ILLUSTRATION: C.W. JEFFERYS, LIBRARY AND ARCHIVES CANADA—C073573 Clockwise from top left: A brigade logo; members of today's David Thompson Brigade; a sketch of the explorer using a sextant to take an observation; a section of the Columbia River; one of the many mountain passes Thompson travelled through. In late June, as schools across the country closed for the summer and families prepared for their annual vacations, 67-year-old Norm Crerar planned to slip into an eight-metre (25-foot) wood-and-Fiberglas canoe with five other paddling enthusiasts at Canal Flats, deep in the southeast corner of British Columbia. Crerar and his team were to lead the David Tho...

PHOTO: DAN BLACK The Royal Tyrrell Museum's cast of a woolly mammoth. In seconds the classroom in Red Deer, Alta., erupts into a loud and prolonged burst of "Ewwwww!" followed by a short, but audible, "That's gross!" Tucked in between those expressions--and originating from somewhere near the back of the class--is a separate, calmer voice, declaring: "Cool!" A hand-sized clump of fossilized dung--possibly dino dung--is what the students at St. Patrick's Community School are reacting to on this sunny day in March 2007. What's also interesting is that the fossil and the students are not even in the same city, let alone the same room. They a...