Kicking Horse Pass, elevation 1627 m, straddles the Continental Divide on the BC-Alberta border, 10 km west of Lake Louise. Sir James Hector and a party of the Palliser Expedition explored the pass in 1858. The peculiar name derives from an incident in which Hector was kicked in the chest by a packhorse. The pass was selected as the route for the transcontinental Canadian Pacific Railway, despite its severe inclines; construction was completed in 1884. The steep rail grades of 4.5% on the BC side of the pass were lessened to 2.2% by construction of Spiral Tunnels (1909), now a popular tourist attraction. The pass, which connects Yoho and Banff national parks, is also crossed by the Trans-Canada Highway.