Arizona State Route 85

Arizona State Route 85 is a north–south highway in southwestern Arizona connecting the United States–Mexico border region near Mexicali with the Phoenix metropolitan area via Yuma, Buckeye, and Gila Bend. The route serves as a corridor between Interstate 8, Interstate 10, and Interstate 17 and links the Sonoran Desert corridor to major transportation nodes such as Yuma International Airport, Phoenix Sky Harbor International Airport, and the Port of Entry, Mexicali. The highway supports regional freight movement, tourism to destinations like Organ Pipe Cactus National Monument and Cabeza Prieta National Wildlife Refuge, and connects communities including Tacna and Auburn.

Route description

SR 85 begins near the United States–Mexico border south of Yuma County and proceeds north through the Colorado River valley toward Yuma. The alignment intersects Interstate 8 just east of Fort Yuma and continues through agricultural lands irrigated by the Yuma Project and canals of the Bureau of Reclamation. North of Mohawk the highway traverses La Paz County and approaches Gila Bend, where it meets Interstate 8 and the historic U.S. Route 80 alignment. From Gila Bend SR 85 runs northeast across the Sonoran Desert toward Maricopa County, passing near Gold Canyon and Dateland before reaching Buckeye and the west side of Phoenix, where it terminates at Interstate 10. The corridor crosses desert ecosystems and important military training areas such as parts of the Barry M. Goldwater Air Force Range and provides access to recreational sites including Kofa National Wildlife Refuge and various state parks.

History

The routing that became SR 85 has origins in early 20th-century auto trails connecting San Diego, Los Angeles, and Phoenix to Mexicali and Yuma. During the era of the United States Numbered Highway System expansion and the New Deal, alignment changes tied SR 85 to improvements associated with Interstate Highway System planning and U.S. Route 60 realignments. In 1936 the state designated the corridor to improve connections between Mexicali crossings and inland Arizona communities; subsequent decades saw paving projects funded by state agencies and federal programs including wartime mobilization efforts that supported roads near Marine Corps Air Station Yuma and Luke Air Force Base. The rise of Interstate 10 and Interstate 8 in the 1950s and 1960s altered traffic patterns, prompting bypasses and transfers of older alignments to county control similar to changes seen with U.S. Route 80 and U.S. Route 60. Late 20th-century growth in Maricopa County led to upgrades in the Buckeye corridor to address commuter flows from exurban development tied to metropolitan expansions around Scottsdale, Mesa, and Chandler.

Major intersections

The highway’s principal junctions link SR 85 with several major corridors and communities: - Southern terminus area: connections serving Mexicali international traffic and local roads to Algodones Dunes. - Junction with Interstate 8 near Yuma linking to San Diego and Gila Bend. - Intersections with state and county routes providing access to Fort Yuma, Dateland, and Tacna. - Concurrency and interchange areas with historic U.S. Route 80 corridors and spur links toward Gila River Indian Community tribal lands. - Northern terminus at Interstate 10 near Buckeye providing freeway access toward Phoenix, Tucson, and interstate freight routes that serve Union Pacific Railroad corridors and distribution centers near Phoenix Sky Harbor International Airport.

Future plans and improvements

Planning efforts by the Arizona Department of Transportation and regional planning organizations such as the Maricopa Association of Governments include capacity upgrades, interchange reconstructions, and safety improvements along the SR 85 corridor. Projects under consideration coordinate with freight mobility initiatives tied to the North American Free Trade Agreement legacy trade flows, expanded logistics at inland ports, and resilience planning related to Arizona water rights and desert conservation areas. Proposals include widening segments near Buckeye to accommodate commuter growth, improving interchanges with Interstate 8 and Interstate 10 to enhance freight movements related to the Ports of Entry network, and implementing wildlife crossings in collaboration with the U.S. Fish and Wildlife Service to reduce vehicle collisions with native species such as those protected in Cabeza Prieta National Wildlife Refuge.

Related routes and designations

SR 85 historically interacted with other numbered routes and designations including segments of U.S. Route 80, U.S. Route 60, Interstate 8, Interstate 10, and feeder state routes serving La Paz County and Yuma County. The corridor’s planning intersects with federal designations affecting National Highway System priorities, desert conservation areas administered by the Bureau of Land Management, and tribal transportation programs with communities such as the Gila River Indian Community and Tohono O'odham Nation.

Category:State highways in Arizona