By 1935, almost all of US 66 between Topock and Peach Springs had been paved. road surfacing had also been completed on all of US 66 between Crookton and New Mexico. The last unpaved sections of US 66 remaining were a section of heading west from Crookton through Cedar Grove and a section heading northeast out of Valentine. Although these two sections were not yet paved, they were surfaced with rock or gravel, meaning all of US 66 at least had improved surfacing. Passage of the Emergency Relief Appropriation Act of 1935 by the United States federal government gave the Arizona State Highway Department the necessary provisions and funding to replace an at-grade railroad crossing in Winslow with an underpass in 1936. The entirety of US 66 in Arizona was paved by 1938. This made US 66 one of the first highways in Arizona to be completely paved. However, the title of first fully paved U.S. Highway in Arizona was taken three years earlier by the second incarnation of US 70, which entered Arizona from California through Ehrenberg and exited near Duncan into New Mexico. Albeit the paving work had been completed long before the Ehrenberg–Duncan route had been designated as part of US 70. On January 24, 1938, the entirety of US 66 between Los Angeles and Chicago was designated as the Will Rogers Memorial Highway by the U.S. Highway 66 Association.