Meanwhile the channel out of Lewis Lake finally collapsed completely, sending a wall of muddy water through the lower lake. For a time, a hundred-foot-high waterfall thundered mud and debris into the valley.
Two days after the first small stream was cut, the Watson River valley was covered with mud, and mud-stained water was visible as far as Lake Bennett and the Mounted Police post on Tagish Lake. Lewis Lake, apart from a few deep holes, had disappeared, its water level lowered by 70 feet. Instead of lower costs, the railway builders now faced increased costs for two unexpectedly large bridges to cross canyons created during the draining of what was once Lewis Lake.
