Cajon Summit
Cajon Summit is a mountain pass at an elevation of 1.301m (4,268ft) above the sea level, located in Southern California in the United States.
The road to the summit is asphalted. It’s called Interstate 15 (I-15). The road links the Los Angeles area ports to the Midwest and eastern US. It has always been an important gateway to southern California. The pass is located between the San Bernardino Mountains and the San Gabriel Mountains. Speed limit is 70 mph (45 mph for trucks). Its steepest grade is 6 % for 4 miles. Using a low gear it is extremely important to conserve trucks brakes. The area is known for high wind, turbulence and fog. The weather over the pass can vary, from foggy days with poor visibility to clear afternoons.
In Spanish, the word cajon means "box". The road gets snow occasionally, sometimes enough to close the pass temporarily. The first road over the pass was built in the 1880s. It has been paved with macadam since 1916. The road was widened further to 20 ft with 5 ft. shoulders, eliminating curves (1932 - 34).