By 1935, the
American Association of State Highway Officials (AASHO) had received two extension requests for
U.S. Route 93 south of what was then its southern terminus in
Glendale, Nevada. Arizona State Highway Engineer T.S. O'Connell requested US 93 extend southwest into California to meet
US 99 in
El Centro. At a later time, he reconsidered and sent a second request for US 93 multiplex with
US 466 over the new
Boulder Dam into Arizona and end at
US 66 in
Kingman. This created a conflict, leading to both proposals being accidentally denied. After a misunderstanding regarding the conflicting proposals from O'Connell, the second proposal was re-evaluated and approved. Thus, US 93 was extended into Arizona. In 1936, the Arizona Highway Department began exploring the possibility of a further extension of US 93. The first extension proposal called for US 93 to end in Phoenix, being extended from Kingman by way of US 66 through
Ash Fork. A new
US 193 was proposed from Phoenix through
Sacaton and
Casa Grande to
Picacho. Upon hearing of the proposed extensions, citizens of
Wickenburg, Arizona,
Wikieup and
Aguila protested to have US 93 run through their towns instead. The protest was considered and the Arizona Highway Department changed its proposal to meet the protester's arguments. The Arizona State Legislature passed a bill instructing the Highway Department to eventually designate and maintain a route for US 93 from Kingman to
US 60 via Wikieup once construction work was completed on existing US 93 within the state. The first extension proposal was modified, asking for the US 93 concurrency with US 66 and US 89 to be signed instead as
US 93T and for the proposed US 193 to become
US 93A. On June 7, 1937, the finalized proposal was submitted to the AASHO, with the US 93T and US 93A suffixes omitted. The proposal was not accepted. On October 11, 1946, the highway between US 89 near Wickenburg and US 66 in Kingman was officially added to the state highway system as State Route 93. The hope was that SR 93 would eventually become the long-awaited extension of US 93 south of Kingman. Between 1956 ad 1961, SR 93 was redirected onto a more direct routing to SR 71 southwest of Congress. In 1954, the SR 93 designation was extended south along US 89, US 60,
US 70,
US 80,
SR 87,
SR 387 and
SR 84 to the United States–Mexico International Border in
Nogales. SR 93 now served the cities of
Phoenix,
Casa Grande and
Tucson. The entirety of SR 93 from Kingman to Wickenburg was officially designated the
Joshua Forest Parkway in 1963. The Arizona Highway Department renewed and modified its earlier extension proposal of US 93 on April 30, 1965. The modified proposal stated the US 93 extension was to take over all of SR 93 between Nogales and Kingman, rather than just the route between Kingman and Wickenburg. During this time, the Burro Creek Bridge had begun construction. The U.S. Route Numbering Committee of the AASHO considered this action on June 28, 1965, but the idea was ultimately denied. According to the AASHO, the route was substandard in many areas, didn't carry nearly enough traffic to justify U.S. Highway status and part of the road had yet to be completed to Wickenburg. Part of the proposal was reconsidered on June 28, 1965, approving an extension of US 93 between Kingman and Wickenburg under the condition that substandard areas of the road were improved quickly. In 1984, SR 93 was truncated south of its junction with
I-10 BL /
SR 85 (
Van Buren Street), at the intersection of Grand Avenue and 7th Avenue in Phoenix. The SR 93 designation was finally retired on August 16, 1991. Though never reaching the Mexican border, US 93 was eventually extended further south from US 89 north of Wickenburg. In 1991, the AASHTO approved a request from the Arizona Department of Transportation to eliminate all of US 89 south of
Flagstaff. Thus, US 93 was extended to its current southern terminus at US 60 in Wickenburg. ==Route description==