still dedicated streets, they remain as the most used and heavily traveled Route 66 segments. However, because of the heavy traffic and later non-historic development along these sections, they are generally the least traveled by Route 66 enthusiasts. Modern guide books that describe how to follow historic Route 66 frequently suggest that when arriving at San Bernardino from the east, enthusiasts should enter Interstate 10 as a bypass for these segments exiting near Santa Monica to experience today's terminus. In 2018, U.S. Bicycle Route 66 was established that follows portions of historic Route 66 within California and other areas in the country. Old Trails Highway From San Bernardino to the Arizona state line US 66 followed the old National Old Trails Highway. The old highway veers away from I-15 between Victorville and Barstow, following the railroad through Oro Grande, Helendale, and Lenwood. Through Barstow, it is Main Street. East of Barstow, the National Old Trails Highway passes through a Marine Corps base, limiting public access and forcing traffic onto I-40. From Daggett, Historic 66 leaves I-40, crossing it three times before winding away through Bagdad, Amboy, and Essex. US 66 was all paved in California by 1935. This area is desert; towns like Amboy originated as Atlantic and Pacific Railroad stops and were sustained by Route 66 traffic during the Mother Road's heyday, then became ghost towns when I-40 bypassed them to the north. From Essex the highway was Goffs Road through Goffs until about 1931, joining I-40 at the US 95 exit. The later alignment is now I-40 east of Essex. The original highway winds around I-40 in the Needles area, before crossing the Colorado River into Arizona. Route description Santa Monica to San Bernardino The original western terminus of Route 66 was in downtown Los Angeles at the intersection of 7th street and Broadway Ave. In 1935, the route was extended to Santa Monica. In Santa Monica, US 66 started at the intersection of Lincoln and Olympic Blvd at U.S. 101A. Route 66 headed north on Lincoln and then turned east onto Santa Monica Boulevard, which was, from the Santa Monica city line with Los Angeles up to U.S. Route 101, added to SR 2 during the 1964 renumbering, the same name it had before 1936. In today's terms, it followed Santa Monica Boulevard to its eastern terminus, then continued to the southeast as Sunset Boulevard up to