The silty Fraser River near McBride, British Columbia at a riverside park.  With a total span of 1,375 kilometers, it begins in the Canadian Rockies spanning northwards & west towards Prince George before meandering straight south & through the Coast Mountains to the Lower Mainland.  The river's gray color is due to rock flour from glaciers in the mountains nearby, leaving a chalky powder (deposits of it appear as the clay mixed w/ the rocks on the beach).  The river maintains this color the entire way as there are no reservoirs built along this wild river, so the silt has nowhere to settle until the port of Vancouver.  This river is also a main artery for chinook salmon to spawn up in this area.