The Sammamish River valley was settled in the late 19th century and served by the Seattle, Lake Shore and Eastern Railroad, built in 1889 from Bothell to North Bend, traveling through Redmond, Issaquah, Fall City, and Snoqualmie. By 1902, several wagon roads were built along the railroad, including a road between Fall City and North Bend, which was incorporated into the Sunset Highway when it was designated as a state highway in 1909. The road from Redmond to North Bend became part of the national Yellowstone Trail in the 1910s, including a section near Redmond that was paved with bricks in 1913. A portion of the Yellowstone Trail, along with unpaved roads from Redmond to Bothell, were designated as a state highway in 1925. The highway was paved in the late 1920s, and was incorporated into the Seattle–Fall City branch of the Sunset Highway (Primary State Highway 2) in 1937. After the opening of the North Bend bypass in 1941, the branch highway was extended to North Bend over the former Sunset Highway.