Editing Interstate 15 (section)

===California===
{{Main|Interstate 15 in California}}

North of its junction with [[California State Route 91|SR&nbsp;91]] in [[Corona, California|Corona]], the route roughly follows the former routes of State Route 31. North of [[Devore, California|Devore]], the highway follows the approximate alignment of historic [[U.S. Route 66|US Route&nbsp;66]] along with [[U.S. Route 91|US&nbsp;91]] and [[U.S. Route 395|US&nbsp;395]]. US&nbsp;395 breaks away at Hesperia and the route continues on a direct path to [[Barstow, California|Barstow]] {{convert|35|mi|km|0}} to the north. Meanwhile, the old alignments of US&nbsp;91 and US&nbsp;66 follow the [[Mojave River]] from [[Victorville, California|Victorville]] to Barstow along the [[National Old Trails Road|National Trails Highway]]. At that point, I-15 follows the old route of US&nbsp;91 exclusively as US&nbsp;66 turned east toward [[Needles, California|Needles]]. For many parts of the highway, high-voltage [[electric power transmission|powerline]]s, such as [[Path 46]] and [[Path 27]], almost all originating from the [[Hoover Dam]], follow the freeway. Many of these link distant power stations to the [[Los Angeles]] metropolitan area.

The southern starting point of I-15 was in 1957 planned to be in [[San Bernardino, California|San Bernardino]], at the interchange with the San Bernardino Freeway (then US&nbsp;70/US&nbsp;99, now [[Interstate 10|I-10]]). This was logical as I-15 was following the old alignment of the historic Route&nbsp;66 which passed through San Bernardino. The segment was completed accordingly.

In 1964, legislation was later passed to extend the Interstate to [[San Diego]]. Instead of extending the existing freeway from the I-10 interchange south, however, the [[California Department of Transportation]] drew a new segment in Devore that "branched" off of the original alignment and bypassed San Bernardino altogether. This segment's alignment is generally northeast to southwest for about {{convert|13|mi|km|0}}. Then, in [[Rancho Cucamonga, California|Rancho Cucamonga]], its directional alignment shifts to north–south where it eventually meets with I-10 (about {{convert|15|mi|km}} west of the original interchange in San Bernardino). The segment that had been built from Devore to San Bernardino was retained as an Interstate, but was renumbered as [[Interstate 215 (California)|I-215]]. Note that during the construction of I-15's present alignment, and for some time afterward, I-215 was numbered as I-15E, and its actual mileage would begin at I-10. I-15 runs for a total of {{convert|287|mi|km|0}} in California.