The Yakima side of a road over Chinook Pass was partially completed in 1914, but then work was abandoned for several years. This section was referred to as the 'Normile Grade'. In 1921 work began again on the Yakima side, below Normile, on the American River. This work was done using horse teams. In 1924, an army tractor was brought in to speed up the work. Work on the west side of the road commenced later, and took longer. The two sides did not meet until 1931 at Tipsoo Lake near the summit.