Wapka Falls and Natural Bridge on the Kicking Horse River. The river carries a lot of glacial silt or flour and the heavy seasonal runoff is still carving this valley floor. The water thundered across the falls and sent spray everywhere. Beautiful. Natural Bridge was a great example of the power of the water as it wore through at a rocky waterfall and hollowed out its own bridge. Still other glaciers feed Emerald Lake with this opaque green color since sunlight can not penetrate the silty water