Tokumm Creek, architect of Marble Canyon, is a classic glacial stream, sometimes choked with silt, other times diamond-clear. Walkers marvel at the creek and how it created this profound slot in the bedrock that is often 30 m (98 ft.) deep, yet barely a metre wide.
In 2003, a forest fire swept through this area. Before the fire, the edge of Marble Canyon was a damp, cool place, home to some flowers and lichens normally found north of the Arctic Circle. With the lush forest gone, it is now a drier place. Wildflowers bloom aplenty—fireweed, groundsel, arnica, four-parted gentian and paintbrush. Thousands of lodgepole pine saplings are green against the charred skeleton of the burnt forest.
Seven bridges span the canyon, which is 39 m (128 ft.) deep near its upper end. The namesake rock is not true marble, but dolomite that has been polished by the silt-laden water to produce a smooth and striking finish. Watch for dippers winging through the spray of the waterfall beneath the uppermost bridge.