The Snow Dome is the well-named hump near the center of the vast Columbia Icefield, the largest glaciated expanse in the Rocky Mountians. Ranking about #12 in height in the Canadian Rockies, it is a popular and relatively easy summit for the ski-mountaineers that flock to the Icefield in spring.
However, perhaps the Snow Dome's greatest claim to fame its status as the only point on the surface of the earth (outside of Antarctica) where water flows into three oceans. Actually, this magic spot is very indeterminate and probably shifts from year to year with the flows of the Columbia Icefield, and appears to be located a ways south of the Snow Dome's summit.
See the peak page for the Snow Dome-South Slope for more information about the actual triple divide point.