Pacific Highway (United States) from the Hudson's Bay Company were the first non-Native Americans to use the route of the future Pacific Highway to move between today's Washington State and "Alta California." During the second half of the 19th Century, mule trains, stagecoaches, and the Central Pacific Railroad also followed the route of the Siskiyou Trail. In the early 20th century, around 1910, entrepreneur Sam Hill lobbied the governments of Washington and Oregon to build automobile roads along the path of the Siskiyou Trail, with the ultimate goal of building a paved auto route from Canada to Mexico. Pacific Highway (United States) Pacific Highway
Washington State Route 510 Washington State Route 510 State Route 510 (SR 510) is a state highway in Thurston County, Washington. The long highway extends southeast from an interchange with (I-5) in Lacey to in Yelm. SR 510 roughly parallels the Nisqually River, the border between Thurston and Pierce counties, between the Fort Lewis and Nisqually Indian Community area to Yelm. The roadway was built by 1916 as a connector from Saint Clair Lake to the Northern Pacific Railway station in Yelm and was designated as Secondary State Highway 5I (SSH 5I) in 1937. The original route of SSH 5I ran from Tumwater east