State Route 14 (SR 14) is a north–south state highway in the U.S. state of California that connects Los Angeles to the northern Mojave Desert. The southern portion of the highway is signed as the Antelope Valley Freeway. The route connects Interstate 5 (I-5, Golden State Freeway) on the border of the city of Santa Clarita to the north and the Los Angeles neighborhoods of Granada Hills and Sylmar to the south, with U.S. Route 395 (US 395) near Inyokern. Legislatively, the route extends south of I-5 to SR 1 in the Pacific Palisades area of Los Angeles; however, the portion south of the junction with I-5 has not been constructed. The southern part of the constructed route is a busy commuter freeway serving and connecting the cities of Santa Clarita, Palmdale, and Lancaster to the rest of the Greater Los Angeles area. The northern portion, from Vincent (south of Palmdale) to US 395, is legislatively named the Aerospace Highway, as the highway serves Edwards Air Force Base, once one of the primary landing strips for NASA's Space Shuttle, as well as the Naval Air Weapons Station China Lake that supports military aerospace research, development and testing. This section is rural, following the line between the hot Mojave desert and the forming Sierra Nevada mountain range. Most of SR 14 is loosely paralleled by a rail line originally built by the Southern Pacific Railroad, and was once the primary rail link between Los Angeles and Northern California. While no longer a primary rail line, the southern half of this line is now used for the Antelope Valley Line of the Metrolink commuter rail system. Linked with US 395, this road also connects Los Angeles with such places as Mammoth Mountain, Mono Lake, Yosemite National Park and Reno, Nevada. SR 14 was part of US 6 prior to truncation in 1964, when US 6 was a coast-to-coast route from Long Beach to Provincetown, Massachusetts. The non-freeway segment of SR 14 from Silver Queen Road north of Rosamond to Mojave is known as Sierra Highway, as is the old routing between I-5 and Silver Queen Road where SR 14 has been moved to a newer freeway alignment. Portions of SR 14 remain signed with names associated with US 6, including Midland Trail, Theodore Roosevelt Highway, and Grand Army of the Republic Highway. Route description SR 14 is part of the California Freeway