You enter the Great Gorge of the Ruth Glacier—the world’s deepest. The ice is 3700 feet deep, some of it more than a thousand years old. The surrounding walls soar 4000-5000 feet above. Were the ice to melt tomorrow, you would witness a spectacle twice as awesome as the Grand Canyon—a gorge a mile wide and nearly two miles high. Watch for climbing camps…These may be the world’s most impressive granite monoliths. You’ll stare in disbelief at mile-high spires of sheer granite with names such as Moose's Tooth, Broken Tooth, and Bear Tooth. 100 miles to the south, these features are very identifiable and really look like animals' teeth. So immense, what appear to be tiny flakes on these walls are actually ledges wide enough to park a tractor trailer. On the right is Mt. Dickey, the highest granite wall in North America. It would take two Yosemites, one stacked atop the other, to equal its height. After fresh snowfalls or in the early morning sun, you might see avalanches raking down it. The sun's warmth releases them into a shower of rock and ice that ricochets for a vertical mile before slamming into the glacier floor, sending reverberations a dozen miles. Experienced climbers recognize avalanche-prone slopes and stay clear...As the Ruth Glacier flows down a steeper gradient, it tears and fractures into a treacherous and virtually impassable 10-square mile section known as the Ruth Ice Fall.