Arizona Borders: States, Map & Complete Guide
Fact-checked • Updated January 11, 2026
Arizona borders five U.S. states: Utah to the north, Colorado to the northeast at the Four Corners point, New Mexico to the east, Nevada to the northwest, and California to the west. The state also shares an international border with Mexico to the south. The Colorado River forms Arizona's entire western border with Nevada and California.
Arizona Border Map
Map showing Arizona's boundaries with five states, Mexico, the Four Corners point, and the Colorado River.
Border Details
Explore each of Arizona's borders in detail. Click any card to learn more.
Utah
Utah forms most of Arizona's northern border along the 37th parallel.
Colorado
Colorado meets Arizona at the Four Corners point.
New Mexico
New Mexico borders Arizona's entire eastern edge.
Mexico
Mexico borders Arizona along the 31st parallel for about 370 miles.
California
The Colorado River forms the entire border with California.
Nevada
The Colorado River creates the border with Nevada.
Which States Border Arizona?
Arizona shares its borders with five U.S. states: Utah to the north, Colorado at the Four Corners point in the northeast, New Mexico to the east, Nevada to the northwest, and California to the west. The Colorado River forms Arizona's entire western boundary.
North: Utah
Utah and Arizona are separated by a border located on Arizona's northern edge. The state line follows the 37th parallel north latitude, creating a straight east-west boundary.
The Arizona-Utah border extends for about 275 miles from Nevada in the west to the Four Corners point in the east. Arizona counties along this border include Mohave, Coconino, and Navajo (and Apache at Four Corners). The border passes through diverse terrain including the Colorado Plateau, red rock country, and portions of the Navajo Nation. Monument Valley straddles this border.
- About 275 miles along 37th parallel
- Straight east-west line
- Monument Valley on border
North-East: Colorado (Four Corners Point)
Colorado and Arizona meet at a single point in Arizona's northeastern corner. This intersection is called Four Corners, where Arizona, Colorado, New Mexico, and Utah all touch.
This is not a traditional border but rather a quadripoint—the only place in the United States where four states meet at one spot. A monument marks the exact location. While Colorado and Arizona don't share a border line, they do share this unique geographic point. Apache County is the only Arizona county that touches this point.
- Only a single point, not a border line
- Four Corners: only U.S. quadripoint
- Monument marks the spot
East: New Mexico
New Mexico and Arizona are separated by a border located on Arizona's eastern edge. The boundary runs roughly north-south from the Four Corners point in the north to Mexico in the south.
The Arizona-New Mexico border extends for about 390 miles. The border follows a straight survey line along approximately the 109th meridian west. Arizona counties along this border include Apache, Navajo, Greenlee, Graham, Cochise, and Santa Cruz. The border passes through diverse landscapes including high desert, mountains, and the Chihuahuan Desert.
- About 390 miles along 109th meridian
- Straight north-south line
- Arizona counties: Apache, Navajo, Greenlee, Graham, Cochise, Santa Cruz
North-West: Nevada (Colorado River Border)
Nevada and Arizona are separated entirely by the Colorado River along Arizona's northwestern edge. The river creates a natural boundary in this region.
The Arizona-Nevada border extends for about 150 miles along the Colorado River. Lake Mead, formed by Hoover Dam, creates much of this border. Only Mohave County in Arizona touches this border. The Hoover Dam sits on this border, with visitors able to stand in both states. Las Vegas, Nevada is located about 25 miles northwest of the border.
- About 150 miles along Colorado River
- Lake Mead forms much of border
- Hoover Dam on border
West: California (Colorado River Border)
California and Arizona are separated entirely by the Colorado River along Arizona's western edge. The river creates a natural boundary running roughly north-south.
The Arizona-California border extends for about 240 miles along the Colorado River from Nevada in the north to Mexico in the south. Arizona counties along this border include Mohave, La Paz, Yuma, and others. Major communities on this border include Yuma, Arizona and cities on the California side. The Colorado River has been dammed and channelized in many sections: along this border.
- About 240 miles along Colorado River
- Entire border formed by river
- Major city: Yuma, Arizona
International Border with Mexico
Arizona shares an international border with Mexico along its southern edge. The border runs for about 370 miles and touches the Mexican state of Sonora.
South: Mexico (Sonora)
Mexico and Arizona are separated by a border located on Arizona's southern edge. The international boundary runs roughly east-west along the 31st parallel north latitude from California in the west to New Mexico in the east.
The Arizona-Mexico border extends for about 370 miles. The border is entirely with the Mexican state of Sonora. Arizona counties along this border include Yuma, Pima, Santa Cruz, and Cochise. Major border crossings include Nogales (Arizona) to Nogales (Sonora), San Luis to San Luis Río Colorado, and Douglas to Agua Prieta. Tucson, Arizona is located about 60 miles north of the border.
- About 370 miles along 31st parallel
- Borders Mexican state: Sonora
- Major crossings: Nogales, San Luis, Douglas
Colorado River: Arizona's Entire Western Border
The Colorado River forms Arizona's entire western border with both Nevada and California, running for approximately 390 miles total. This makes the Colorado River one of the most important water features defining state boundaries in the American West. The river flows through dramatic canyons, including the Grand Canyon in northern Arizona, before forming the state border. Lake Mead and Lake Havasu are major reservoirs along the border. The Colorado River provides crucial water resources for Arizona, California, Nevada, and Mexico through a complex system of dams, aqueducts, and water rights agreements. The river has been heavily managed for water supply, hydroelectric power, and flood control.
Four Corners: Where Four States Meet
Arizona is one of the Four Corners states, meeting Utah, Colorado, and New Mexico at a single point in the northeast. This spot is called Four Corners—the only place in the United States where four states touch. A monument marks the exact location where visitors can stand in all four states at once. This unique geographic feature has made the Four Corners region a popular tourist destination. The monument is located on Navajo Nation land. The Four Corners area is part of the Colorado Plateau and features spectacular red rock landscapes, canyons, and desert terrain.
Grand Canyon and the Colorado Plateau
Arizona's northern border region sits on the Colorado Plateau, a vast elevated region characterized by dramatic canyons, mesas, and rock formations. The Grand Canyon, carved by the Colorado River over millions of years, is located in northern Arizona near the Utah border. The canyon is up to 18 miles wide, 277 miles long, and over a mile deep, making it one of the Seven Natural Wonders of the World. Grand Canyon National Park attracts millions of visitors annually. The Colorado Plateau extends into Utah and other neighboring states, creating the distinctive landscape that characterizes much of Arizona's border regions.
Key Facts & Statistics
This table shows every border Arizona shares, organized by direction and type.
Arizona borders exactly five U.S. states
Frequently Asked Questions
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Sources & References
This article has been researched using authoritative sources to ensure accuracy and reliability.