The lowest-elevation glacier in the contiguous United States, descending the north face of Mount Rainier into a forest of western hemlock and Douglas-fir instead of stopping above the tree line. It is also the thickest glacier in the lower 48. The standard approach is the Carbon River entrance on the park's northwest corner, where the road has been a foot and bike trail since the floods of November 2006 washed it out. The Wonderland Trail crosses the Carbon River on a long suspension bridge near the snout. The water below runs grey with rock flour from ice grinding bedrock above.