The Tehachapi Mountains (; Kawaiisu: Tihachipia, meaning "hard climb") are a mountain range in the Transverse Ranges system of California in the Western United States. The range extends for approximately in southern Kern County and northwestern Los Angeles County and form part of the boundary between the San Joaquin Valley and the Mojave Desert. Geography The Tehachapis form a geographic, watershed, habitat, and rain shadow divide separating the San Joaquin Valley to the northwest and the Mojave Desert to the southeast. The Tehachapis' crest varies in height from approximately . They are southeast of Bakersfield and the Central Valley, and west of Mojave and the Antelope Valley. The range runs southwest to northeast (SW-NE) connecting the Southern Sierra Nevada range on their northeast with the San Emigdio Mountains on the west and Sierra Pelona Mountains on the southwest. The Tehachapis are delineated from the San Emigdio Mountains by Tejon Pass at the range's western end. The dramatic incline of Interstate 5 from the San Joaquin Valley floor up to the pass, is regionally referred to as The Grapevine, after Grapevine Canyon which it follows between the northern slopes of the two mountain ranges and is sometimes extended to include the portion of Interstate 5 on the southern side of Tejon Pass, especially during snow closures. The canyon was named after native grapevines, the California grapevine (Vitis californica), found at springs on its slopes. The California State Water Project is to the east, with the California Aqueduct pumped by the Edmonston Pumping Plant over/through the Tehachapis to Castaic Lake reservoir. The Tehachapis are delineated from the Sierra Pelona Mountains by California State Route 138 at the range's southwestern end, connecting Interstate 5 and the Antelope Valley. The Tehachapis are delineated from the Sierra Nevada by Tehachapi Pass and State Route 58 at the range's northeastern end, connecting the San Joaquin Valley and Mojave Desert. The Union Pacific north/south railroad line, with the famous Tehachapi Loop, crosses here also. The Tehachapi Pass Wind Farm is on its eastern side. The Tehachapis, though neither as long or high as other California mountain ranges, are often considered the topographic feature that separates this part of Northern California from Southern California, with the geographic boundary often being Kern County. Some historians consider that California averted a potential split into two separate states – "North California" and "South California" – from the early 20th century Ridge