It is listed on the National Register of Historic Places as an engineering accomplishment, a "marvel" which was an achievement of the early good roads movement.

Its 1974 NRHP nomination asserts that it "will be remembered as one of the marvels of highway engineering, built when cars did not travel much more than 25 miles per hour (40 km/h)."

[3][4][5][6][7] The contract for the original road, 22 miles (35 km) from the mouth of White Bird Creek at the Salmon River to Grangeville, was awarded in late 1918.

[8] Completed in 1921 and first paved in 1938, it rose slightly higher to 4,429 feet (1,350 m), due to the absence of a summit cut.

[6][7] Farmers kept water troughs at a few of the precarious switchbacks for their livestock and folks who frequently traveled the road knew their exact locations, as they were a welcome stop for over-heated cars.