California State Route 78

State Route 78 is a state highway in the U.S. state of California. It runs from Oceanside east to Blythe, traversing nearly the entire width of the state. The freeway section in the North County of San Diego was built in the middle of the twentieth century in several stages. The highway was designated as a state road in 1934 but was not officially designated until 1959.

About California State Route 78 in brief

Summary California State Route 78State Route 78 is a state highway in the U.S. state of California. It runs from Oceanside east to Blythe, traversing nearly the entire width of the state. SR 78 was one of the original state highways designated in 1934, although portions of the route existed as early as 1900. The freeway section in the North County of San Diego was built in the middle of the twentieth century in several stages, including a transitory stage known as the Vista Way Freeway, and has been improved several times. An expressway bypass of the city of Brawley was completed in 2012. There are many projects slated to improve the freeway due to increasing congestion in the region. The route is a freeway through the heavily populated cities of northern San Diego County and a two-lane highway running through the Cuyamaca Mountains to Julian. It is also a scenic highway for its length in Anza-Borrego Desert State Park and provides access to the town of Borrego Springs via CR S3. In Imperial County, SR  78 intersects with SR 86, running concurrently with it southwest of the Salton Sea and northwest of San Felipe Creek. As it nears the Colorado River and Arizona border, it briefly passes through Cibola Verde National Wildlife Refuge before entering Palo Verde. It turns northeast towards north towards Bly the and eventually ends at I-10 in Riverside County. It was not designated east of Bawley until 1959. The highway was designated as a state road in 1934 but was not officially designated until 1959, when it was added to the list of state roads in San Diego and Imperial Counties.

It has a total length of 1,856 miles (1,922 km) and is one of only a handful of state highways in the United States that are entirely in the deserts of Southern California and Northern California. Its western terminus is at Interstate 5 and its eastern terminus was at Interstate 15 in Escondido, where it has an interchange with I-15. It also runs through the small community of Glamis before turning north and passing through an area of sand dunes on the way to its terminus in Bly The. The road ends at the intersection with Broadway, where the freeway abruptly ends. SR 78 runs concurrently with SR 79 across the headwaters of the San Diego River and through the hamlet of Wynola, briefly entering Cleveland National Forest before reaching Julian and entering the town as Washington Street. It continues on a winding mountain alignment through Witch Creek to Santa Ysabel where it meets SR 79. It then turns east onto Main Street and travels through downtown Julian before SR79 diverges south towards Cuymaca and SR 78 heads northeast as Banner Road. It ends at a junction called Scissors Crossing; CR S2 runs concurrently in a wrong-way concurrency with SR 79 and SR 86 to the south towards El Centro, where SR86 splits south towards the south.