Route 138 is a major highway in the United States, primarily located in the state of California. It stretches approximately 100 miles, connecting various cities and towns, including San Bernardino and Los Angeles. The route is known for its scenic views and accessibility to several recreational areas. In addition to its role as a transportation corridor, Route 138 serves as a vital link for local communities. It provides access to outdoor activities, such as hiking and camping, particularly in areas like the San Gabriel Mountains. The highway is also important for commerce, facilitating the movement of goods and services across the region.