This river was named in 1858, when James Hector, a member of the Palliser Expedition, was kicked by his packhorse while exploring the river. Hector survived and named the river and the associated pass as a result of the incident. The Kicking Horse Pass, which connects through the Rockies to the valley of the Bow River, was the route through the mountains subsequently taken by the Canadian Pacific Railway when it was constructed during the 1880s. The railway's Big Hill and associated Spiral Tunnels are in the Kicking Horse valley and necessitated by the steep rate of descent of the river and its valley. You can just see a train on the far left of the image.
This is a glacial fed river hence the aqua colour. A wild, untamed river discovered in the 1800s on the famous Palliser Expedition.