Part 1; the history of the Dog Valley Grade
The first documented wagon crossing of the Sierra Nevada Mountains was made in 1844 by the Townsend-Murphys Party. From the vicinity of modern-day Verdi, Nevada the Townsend-Murphy Party traveled westward via the Truckee River Canyon towards what is known now as Donner Lake. This routing proved hazardous which led to an alternate routing being scouted through Dog Valley by Caleb Greenwood in 1845. The Dog Valley Grade would be favored by most immigrant parties including the ill-fated Donner Party during the Fall of 1846.
Much of the early history of the Dog Valley Grade is discussed in the September 1950 Centennial Edition of California Highways & Public Works. The volume notes the difficulties faced by the Townsend-Murphy Party in the Truckee River Canyon and the utility of the Dog Valley Grade.
The below illustration found in the September 1950 California Highways & Public Works depicts the Dog Valley Grade (1) from the Nevada state line west to Truckee. The Dog Valley Grade is shown intersecting with the Henness Pass Road (2) in Dog Valley and then modern US Route 40 in Truckee.
During 1912 Indiana Businessman Carl G. Fisher conceptualized the Lincoln Highway as a major transcontinental Auto Trail. The Lincoln Highway was formally dedicated on October 31, 1913, and was aligned west of Fallon via split branches over the Sierra Nevada Mountains. The original northern branch of the Lincoln Highway (displayed in blue) is shown on the Lincoln Highway Association's Official Map from Verdi, Nevada via the Dog Valley Grade to Truckee, California.
The Victory Highway was formally organized during 1921 as a coast-to-coast highway aligned from New York to San Francisco. The Victory Highway Association lived on after the creation of the US Route System and became the US Route 40 Association in 1938.
The initial draft of the US Route System was approved by the Secretary of Agriculture during November of 1925. The US Route System within California was approved by California Highway Commission with no changes recommended by January 1926. The alignment of US Route 40 east of Sacramento was planned to follow the existing Northern Branch of the Lincoln Highway and Victory Highway over LRN 3, LRN 17, LRN 37 and LRN 38 to the Nevada state line at Verdi.
Thusly US Route 40 appears on the 1925 Rand McNally Map of California east of Sacramento to Verdi. Conceptual US Route 40 is shown following the Dog Valley Grade east of Truckee.
The May 1926 California Highways & Public Works noted LRN 38 in the Truckee River Canyon between Truckee and the Nevada state line as having been fully graded. The new segment of LRN 38 is stated to have a planned opening on June 10th, 1926, as a bypass to the Dog Valley Grade.