The ghost highway that once served as the West Coast's main street
In short: Before Interstate 5 dominated the landscape, U.S. Route 99 was the primary artery of the American West. Known as the Golden State Highway, it carried Dust Bowl migrants and pioneers across three states, tracing ancient footpaths that predate modern civilization by centuries.
U.S. Route 99 was a major north–south highway spanning from the Mexican border at Calexico to the Canadian border at Blaine. Assigned in 1926, it served as the primary corridor for West Coast travel until it was largely replaced by Interstate 5. During the 1930s, it gained cultural significance as a vital path for Dust Bowl immigrant farm workers moving through California.
The highway's geography reveals deep historical layers. An extensive section exceeding 600 miles from Stockton, California, to Vancouver, Washington, closely follows the Siskiyou Trail. Native American footpaths, which linked California's Central Valley to the Pacific Northwest, formed the basis for this path. During the 1820s, individuals from the Hudson's Bay Company became initial non-Indigenous people to travel along this way.
The transition from a scenic highway to a modern freeway involved complex renumbering. In 1963, a bill launched a program to simplify California's numbering system, leading to the phasing out of US 99 starting in 1964. While much of it was decommissioned by 1972, fragments remain: parts are now state routes (like SR 99 in California), and some sections in Washington exist as local city streets or specific tunnels like the one replacing the Alaskan Way Viaduct.
Today, the legacy of Route 99 persists through various designations. In Oregon, it provides surface-level access to towns served by I-5, while in California, a newly enacted Historic U.S. Route 99 preserves the original path from Indio down to the Mexican border.
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Sources
- Summary by Intellect · source: U.S. Route 99
- Also: Wikidata — U.S. Route 99 · CC0
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