Mount Robson

December 06, 2010


: Stu Witmer
Summary author: Stu Witmer

December 2010 Earth Science Picture of the Day Viewer's ChoiceAt 12,972 ft (3,954 m) Mount Robson (above) is the highest peak in the Canadian Rockies. Mount Robson’s peak stands over 10,000 ft (3000 m) above the Fraser River valley giving it the highest base to peak elevation in all of the North American Rocky Mountains. The Rocky Mountains include at least 100 separate ranges, which are frequently divided into four groups. Two of those groups, the Canadian Rockies and the Northern Rockies of Montana and northeastern Idaho, consist predominately of limestone and shale. Mount Robson is situated at the bottom of an extensive syncline. This creates the nearly horizontal appearance of the sedimentary rocks that, in turn, sit atop quartzite metamorphic rock. The mountain is known by some climbers as "The Great White Fright" and was first climbed in 1913.

Most likely, the mountain’s name is a mispronunciation of Colin Robertson’s last name. Mr. Robertson worked for both Hudson's Bay and the North West Companies in the early nineteenth century when the valley was a gathering place for trappers. The local Shuswap tribes have named it “The Mountain of the Spiral Road” due to the tilted horizontal rock layers that hold the snow and look like a path circling up the mountain. Other names include “Snow Cap Mountain” and “Cloud Cap Mountain.” Due to its size, shape and location, Mount Robson readily catches Pacific moisture, resulting in much higher precipitation values than in surrounding areas and all but continuous cloud cover. When the prevailing westerly winds rise to pass over the peak they can cool and condense into an orographic cloud. The day we visited Mount Robson it was sporting a dashing banner cloud. Banner clouds form when air flows around a peak rather than over it as with a cap cloud. Photo taken the morning of September 22, 2009.

Photo Details: Camera: NIKON E5700; Focal Length: 71.2mm (35mm equivalent: 280mm); Aperture: f/7.4; Exposure Time: 0.0021 s (1/485); ISO equiv: 200.

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