The Icefields Parkway South of Jasper - Photo by Mark Basso
Centered more or less around Jasper, Alberta, this area features some of the finest difficult-extreme rivers anywhere, and there are more than a few. The Columbia Icefields is 45 minutes south of the town of Jasper. It represents the source of rivers flowing to each ocean. You have the Athabasca drainage (the true headwaters of the Mackenzie) the Fraser Drainage, and the North Saskatchewan Drainage. These three major drainage's have countless tributaries. In the Eastern and Northern parts of the Central Rockies, you get distinct sedimentary geology, with rivers cutting through and across layers of shale, sandstone, limestone and dolomite. Often this can lead to broken ledges, falls, and deep canyons. As you head West towards Jasper, and eventually the Fraser, you start to get into a lot of harder metamorphic rocks, which tends to lead to more defined bedrock, and bigger boulder runs.