To complete the Pacific railway as quickly as possible, a decision was made to delay blasting a lengthy tunnel through Mount Stephen and instead build a temporary line over it. Instead of the desired 2.2% grade (116 feet to the mile) a steep 4.5% (some sources say 4.4%) grade was built in 1884. This was one of the steepest adhesion railway lines anywhere. (4.5% = 1 in 22.22). It descended from Wapta Lake to the base of Mount Stephen, along the Kicking Horse River to a point just west of Field, then rose again to meet the original route.