U.S. Highway 99

From Academic Kids

Missing image
Detail from antique road map of US 99 through California. Notice 99E and 99W near the north end.

See also: Oregon Highway 99

U.S. Highway 99 was the West Coast's main north-south route until 1964, one of the original United States highways first proposed in 1926 and one of the few highways that ran from Mexico to Canada. Known also as the "Golden State Highway" and "The Main Street of California," US 99 was an important route in California throughout much of the 1930s as a route for Dust Bowl immigrant farm workers to traverse the state. Prior to 99's construction, it was an important stagecoach route linking the two international borders. Given the highway's importance to California during its existence, this article will focus mainly on its route through that state.



The highway started at the border with Baja California in Calexico, California. It then continued north along the western shore of the Salton Sea. The stretch is now known as California State Highway 86. 99 continued along present-day California State Highway 111 through Coachella to its intersection at Dillon Road with another major US route signed as both US 60 and US 70.

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Highway 99 between Lebec and Bakersfield, 1943. View is to the north

Now multiplexed as US 60/70/99, the highway continued north through Indio and turned west toward Los Angeles paralleling the route of modern Interstate 10. In Beaumont, 60 split off on its own westward trek to Los Angeles. The highway through Beaumont (known as Ramsey Street) was bypassed the new superhighway version of 60/70/99 that would later wear Interstate 10 shields. The edges of the old US 60 shield at the replacement interchange's overhead sign are clearly visible today underneath the California State Highway 60 shield that covers it up. US 70 ended in downtown LA while 99 turned north once again more or less following the route of today's Interstate 5, up and over Grapevine Hill in the Tehachapi Mountains to the San Joaquin Valley. 99's original alignment over the hill was known in its earliest days as the Ridge Route, the first highway directly linking the Los Angeles Basin to the San Joaquin Valley. Built in 1915, that alignment between Castaic and Highway 138 in Gorman is listed on the National Register of Historic Places. Although the Ridge Route is rather narrow and winding by today's standards and marked as "not a through road" at its southern end, the roadway is in good condition and is, in fact, still passable even though it was bypassed in 1933 by the three-lane "Alternate Ridge Route." From the southern tip of the San Joaquin Valley at the foot of the Grapevine, US 99 then continued arrow-straight to Sacramento where it split into two highways, 99E and 99W. The two highways rejoined in Red Bluff and continued once again as US 99 through Oregon, Washington and to the border with British Columbia, becoming British Columbia provincial highway 99.

Decommissioning and replacement routes

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US 99 "Ridge Route Alternate," 1948

By 1968, US 99 was completely decommissioned with the completion of I-5, but the highway's phasing out actually began July 1, 1964 thanks to the passage of Collier Senate Bill No. 64 on September 20, 1963. The bill launched a major program designed to greatly simplify California's increasingly complicated highway numbering system and eliminate multiplexed postings like the aforementioned 60/70/99. The highways that replaced it are:

  • SR-111 and SR-86 between the Mexican border and Indio.
  • I-10, replacing US 60 and US 70 between Indio and Los Angeles as well.
  • I-5 from north of downtown all the way to its modern-day split in Wheeler Ridge before 99's final decommissioning in 1968.

State highway 99

All three states have replaced some portions of US 99 with state highways of the same number:

US 99 and the white line

Though US 99 never achieved the fame or romance that was enjoyed by another California highway, the world-famous Route 66, it was quite possibly a more important one as it linked the entire state, unlike 66. Also, US 99 was the progenitor of an important innovation in highway safety. Doctor June McCarroll worked as a nurse for the Southern Pacific Railroad soon after US 99 opened. Her office in Coachella bordered on the new highway (today a part of SR-86) and was the scene of many a head-on collision.

After much lobbying on her part, Nurse McCarroll took it upon herself to paint a stripe down the middle of the highway, which effectively kept the two lanes of traffic separated. This was the first ever highway marking of its kind and was soon adopted worldwide. A stretch of nearby Interstate 10 has been named in her honor.

Related US Routes

External links

Template:US Highways


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