[citation needed] US 66 continued to be signed east of Pasadena until 1974, when it was removed, and the remaining separate section became SR 66.

In 1977, "Hotel California" alluded to Route 66 in its opening lines, "On a dark desert highway, cool wind in my hair, Warm smell of colitas rising up through the air, Up ahead in the distance, I saw a shimmering light, My head grew heavy and my sight grew dim, I had to stop for the night".

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.

East of Barstow, the National Old Trails Highway passes through a Marine Corps base, limiting public access and forcing traffic onto I-40.

Prior to the opening of the Arroyo Seco Parkway, US 66 began north on Broadway which curves east, ending at Mission Avenue.

The city of Glendora renamed their segment of Alosta Avenue to Route 66; the highway is known as Foothill Boulevard again when it enters into San Dimas.

The motel has been closed for years as the town died when Interstate 40 in California diverted traffic ten miles further north.

More recently, the Roy's filling station and café have operated at least sporadically in an attempt to preserve this landmark for tourism.

Its visitors include Elvis Presley, reported to have kicked the jukebox and left without dining after finding none of his own records among the available selections.

[9] Route 66 has attracted campers since the Great Depression era, where The Grapes of Wrath describes a large but primitive riverside campground as one of the first sights when arriving in Needles, California from Arizona.

Needles later became the site of the Carty's Camp cabins seen briefly in John Ford's 1940 film version of "The Grapes of Wrath" (now a deteriorating ghost tourist court) and the later adjacent 66 Motel (which currently offers long-term rental only).

The 1924 Aztec Hotel in Monrovia, a National Historic Landmark in the San Gabriel Valley, is notable for its Mayan Revival architecture.

The historic 1916 Trails Arch Bridge spanning the Colorado River from Topock, Arizona to Needles, California still stands but is no longer open to traffic as the roadbed has since been removed to carry a natural gas pipeline.