The National Old Trails Road (NOTR) portion that later was Route 66 between Barstow and Oro Grande, California. In the early 1900s, the use of the automobile began to grow and better roads became necessary. The National Old Trails planned a road from Los Angeles to New York, and they aligned it next to the Atchison Topeka & Santa Fe railroad tracks from Cajon Pass to Needles. The road passed through Oro Grande. Here they appear to be grading the future roadway using slip, Fresno scrapers pulled by mules and possibly using a Holt crawler tractor in the back. Some of the original sections of Route 66 and other highways of that time have a lot of curves to go around hills and valleys because of the limitations of the equipment. The top picture was taken in the year 1917 showing the new improvement of the existing 10-foot wide roadway of the 1849 Santa Fe & Salt lake Trail.
This "then & now" photo is courtesy of Roger Starbuck.