 By 1929, this road had been designated as State Route 20, and was shown to parallel the Eureka and Palisade Railroad connecting Eureka to State Route 1/US 40 (today's I-80) further west of Carlin via Palisade.SR 20 was mostly upgraded to a gravel road by 1946.Except for the portion between Palisade and US 40, the road was completely paved by 1956—a road connecting just south of Palisade directly to Carlin (approximating today's alignment of the northernmost reaches of SR 278) was also paved by this time.