Establishment U.S. Route 93 was not one of the original
U.S. highways proposed in the 1925 Bureau of Public Roads plan. However, the revised numbering plan approved by the
American Association of State Highway Officials (AASHO) on November 11, 1926 established US 93 from the Canada–US border near
Eureka, Montana south through
Montana and
Idaho to a southern terminus at
Wells, Nevada. The establishment of the highway was reflected on Nevada's 1927 official highway map. The Nevada section was approximately , commissioned along what was then the northern portion of
State Route 13. AASHO, at its June 8, 1931 meeting, approved a southerly extension of US 93 south to
Glendale, Nevada. • From Wells, US 93 continued southeast along the remainder of SR 13 to its terminus at
Lages Station. • At Lages Station, the highway turned south, overlapping the southern portion of
State Route 24 to Magnuson's Ranch. • At Magnuson's Ranch, US 93 followed
State Route 2 south for to
Ely. • The highway was then routed concurrently along the entirety of the nearly
State Route 7, running southeast from Ely through Connor's Pass, south through
Pioche to
Caliente, west to
Crystal Springs and then southeast through
Alamo and
Moapa before terminating at
U.S. Route 91/
State Route 6 in Glendale. At the request of the
Arizona State Highway Department, the AASHO route numbering committee approved another extension of US 93 in 1935. This shifted the southern terminus south to
Kingman, Arizona by way of
Las Vegas. The highway was again extended along existing highways: The first major shift of US 93 occurred in 1967, when a new highway connection was completed between US 91 (now I-15) and a point northwest of Glendale. The new alignment was oriented more north–south, shortening the distance between the Las Vegas area and Caliente by . The old section of US 93 northwest of Glendale paralleling the
Muddy River remained as State Route 7, and was renumbered in 1976 to
State Route 168. In 1982, a "truck bypass" along the upper reaches of Hemenway Wash, to skirt the central portion of
Boulder City and allow a straighter, more steady climb for commercial vehicles, was nearing completion. But by the time this new route opened, it had been signed as mainline US 93, with the old, winding route of US 93 on the Nevada Highway (original SR 26) through town being changed to
SR 500. This state highway designation was later dropped and that roadway is now maintained by Boulder City as "Nevada Way". The western end of this 1982 bypass was also later realigned from Colorado Street south to intersect directly at Buchanan Boulevard (in place of a wye intersection with Nevada Way a block to the east at Joshua Street), by using a small portion of abandoned railroad right-of-way. A shopping center now sits where the original truck bypass alignment once ran. US 93 was realigned again on October 19, 2010, when the
Mike O'Callaghan–Pat Tillman Memorial Bridge over the Black Canyon of the
Colorado River opened to vehicular traffic. With that, the highway no longer passes over Hoover Dam, and the state-maintained portion of the replaced route was renamed as Hoover Dam Access Road (
SR 172). In 2011, US 93 from Buchanan Boulevard to the Nevada terminus of the Hoover Dam Bypass was expanded to four through lanes with dedicated turn lanes at major intersections to better handle increased traffic loads from the Hoover Dam Bypass until its long-planned companion freeway around Boulder City was completed in 2018. On August 9, 2018, US 93 was rerouted onto the Boulder City Bypass around the historic town. The most recent previous alignment (1982–2018) through the heart of Boulder City and along Hemenway Wash has now been re-signed as
U.S. Route 93 Business. ==Major intersections==