Arizona Counties. List Alphabetically (and by Population)
How many counties are there in Arizona? As of 2024, there are a total of 15 counties in the state of Arizona. Among them, Mohave County is the oldest one (established in 1864) while La Paz County is the youngest (established in 1983). With population of 3,990,181, Maricopa County is the most populated. The biggest county by land area is Coconino County (48,332 km²) and the smallest is Santa Cruz County (3,206 km²).
Largest Counties in Arizona
1. Coconino County
County Seat: Flagstaff
- Area: 18,661 square miles
- Population: Approximately 145,101 (2020 census)
- Area Codes: 928
- Latitude: 35.1983° N
- Longitude: 111.6513° W
Location and History
Coconino County is located in the northern part of Arizona and is the second-largest county by area in the United States. The county was established on February 18, 1891, and its name is derived from the Hopi word “Cohonino,” referring to the Havasupai people. Coconino County is known for its diverse landscapes, ranging from the vast pine forests around Flagstaff to the arid deserts of the Grand Canyon. The region has a rich Native American history, particularly with the Navajo and Hopi tribes, and has long been a cultural and transportation hub in the Southwest. Flagstaff, the county seat, developed as a lumber town and later became a key stop along Route 66.
Major Highways and Landmarks
Coconino County is served by major highways, including Interstate 40, which runs east-west through Flagstaff, and Interstate 17, which connects Flagstaff to Phoenix. U.S. Route 89 is another significant route, providing access to the Grand Canyon and other northern Arizona attractions. The county is home to several major landmarks, including the Grand Canyon National Park, one of the most famous natural wonders in the world, and the San Francisco Peaks, the highest mountains in Arizona. The Lowell Observatory in Flagstaff is also notable, where Pluto was discovered in 1930.
2. Pima County
County Seat: Tucson
- Area: 9,189 square miles
- Population: Approximately 1,043,433 (2020 census)
- Area Codes: 520
- Latitude: 32.2226° N
- Longitude: 110.9747° W
Location and History
Pima County is located in the southern part of Arizona, bordering Mexico. It was established on November 9, 1864, as one of the original counties of the Arizona Territory. The county is named after the Pima Native American tribe, who have lived in the region for centuries. Tucson, the county seat, is one of the oldest continuously inhabited areas in the United States, with a history dating back over 4,000 years. The area was originally part of Mexico before becoming part of the United States through the Gadsden Purchase in 1854. Tucson grew as a key stop on the Southern Pacific Railroad and developed into a major cultural and educational center, particularly with the founding of the University of Arizona in 1885.
Major Highways and Landmarks
Pima County is accessible via major highways such as Interstate 10, which runs east-west through Tucson, and Interstate 19, which connects Tucson to Nogales at the U.S.-Mexico border. U.S. Route 86 and State Route 77 also serve the area. Significant landmarks include Saguaro National Park, which preserves the iconic saguaro cactus, and the Arizona-Sonora Desert Museum, a world-renowned natural history museum. The Mission San Xavier del Bac, a historic Spanish mission, and the Pima Air & Space Museum, one of the largest aerospace museums in the world, are other key attractions.
3. Apache County
County Seat: St. Johns
- Area: 11,218 square miles
- Population: Approximately 66,021 (2020 census)
- Area Codes: 928
- Latitude: 34.5053° N
- Longitude: 109.3611° W
Location and History
Apache County is located in the northeastern corner of Arizona, bordering New Mexico. It was established on February 24, 1879, from parts of Yavapai County and named after the Apache Native American tribe. The county is home to a significant portion of the Navajo Nation, the largest Native American reservation in the United States. The area’s history is deeply intertwined with the Navajo and Apache peoples, who have inhabited the region for centuries. St. Johns, the county seat, was founded by Mormon settlers in the late 19th century and has remained a small, agricultural community.
Major Highways and Landmarks
Apache County is traversed by U.S. Highways 60, 64, and 191, which provide critical connections across this vast and rural area. The county is home to several important landmarks, including the Petrified Forest National Park, known for its large deposits of petrified wood and colorful badlands. The Canyon de Chelly National Monument, located on Navajo land, is another significant site, featuring ancient cliff dwellings and stunning red rock formations. The county also includes parts of the Apache-Sitgreaves National Forests, offering outdoor recreation opportunities in its dense forests and alpine meadows.
4. Mohave County
County Seat: Kingman
- Area: 13,461 square miles
- Population: Approximately 213,267 (2020 census)
- Area Codes: 928
- Latitude: 35.1894° N
- Longitude: 114.0526° W
Location and History
Mohave County is located in the northwestern part of Arizona, bordering Nevada, California, and Utah. It was one of the original four Arizona counties, established on November 8, 1864. The county is named after the Mohave Native American tribe, who traditionally lived along the Colorado River. Kingman, the county seat, was founded in the 1880s as a railroad town and later became an important stop on Route 66. The county’s history is marked by its role in mining, particularly in gold and silver, and its strategic location along the Colorado River.
Major Highways and Landmarks
Mohave County is served by major highways, including Interstate 40, which runs through Kingman, and U.S. Highways 93 and 95, which provide north-south routes. The county is home to several major landmarks, including the Grand Canyon’s West Rim, where the famous Skywalk is located, offering breathtaking views over the canyon. Lake Havasu, known for the London Bridge and its recreational opportunities, is another key attraction. The county also includes parts of the Mojave Desert, offering unique landscapes and historical sites such as the ghost town of Oatman, a former gold mining town.
5. Navajo County
County Seat: Holbrook
- Area: 9,959 square miles
- Population: Approximately 106,717 (2020 census)
- Area Codes: 928
- Latitude: 34.9056° N
- Longitude: 110.1620° W
Location and History
Navajo County is located in northeastern Arizona and was established on March 21, 1895, from parts of Apache County. It is named after the Navajo Nation, which covers a significant portion of the county. Holbrook, the county seat, was founded as a railroad town in the 1880s and became known for its rough frontier days, including conflicts with cattle rustlers and outlaws. Navajo County has a diverse cultural history, with significant Navajo, Hopi, and Anglo-American influences. The county’s economy has traditionally been based on agriculture, ranching, and timber, with tourism playing an increasingly important role.
Major Highways and Landmarks
Navajo County is traversed by Interstate 40, which follows the route of the historic Route 66, and U.S. Highways 60 and 191. The county is home to several notable landmarks, including the Petrified Forest National Park, which extends into Navajo County, and the Painted Desert, known for its colorful, stratified layers of rock. The Hopi Reservation, which is entirely surrounded by the Navajo Nation, is another significant cultural site. The historic Wigwam Motel in Holbrook, a Route 66 icon, is a popular stop for tourists traveling through the region.
6. Maricopa County
County Seat: Phoenix
- Area: 9,224 square miles
- Population: Approximately 4,420,568 (2020 census)
- Area Codes: 480, 602, 623, 928
- Latitude: 33.4484° N
- Longitude: 112.0740° W
Location and History
Maricopa County is located in the south-central part of Arizona and is the most populous county in the state. It was established on February 14, 1871, and named after the Maricopa Native American tribe. Phoenix, the county seat and state capital, has grown from a small agricultural community into one of the largest cities in the United States. The county’s history is marked by its transformation through irrigation projects, which turned the arid desert into fertile farmland, and later by the explosive growth of the Sun Belt. Maricopa County is now a major economic and cultural hub, with a diverse population and economy.
Major Highways and Landmarks
Maricopa County is a major transportation hub, with Interstates 10 and 17 intersecting in Phoenix, and U.S. Highways 60 and 93 providing additional connectivity. Significant landmarks include the Desert Botanical Garden, showcasing the unique flora of the Sonoran Desert, and Camelback Mountain, a popular hiking destination. The county is also home to major cultural institutions such as the Heard Museum, which focuses on Native American art and history, and the Phoenix Art Museum. The historic Roosevelt Row in downtown Phoenix is a vibrant arts district, reflecting the city’s cultural diversity and creativity.
7. La Paz County
County Seat: Parker
- Area: 4,514 square miles
- Population: Approximately 16,557 (2020 census)
- Area Codes: 928
- Latitude: 34.1500° N
- Longitude: 114.2890° W
Location and History
La Paz County is located in western Arizona along the Colorado River, bordering California. It is the newest county in Arizona, established in 1983 from the western portion of Yuma County. The county is named after the historic town of La Paz, which was a major mining settlement during the gold rush era. Parker, the county seat, developed as a result of the construction of the Parker Dam on the Colorado River in the 1930s. The region’s history is closely tied to the river, which has been a critical resource for agriculture, recreation, and water management.
Major Highways and Landmarks
La Paz County is served by U.S. Highway 95, which runs north-south along the Colorado River, and Interstate 10, which crosses the southern part of the county. Key landmarks include the Colorado River Indian Tribes Reservation, which spans both Arizona and California and is home to the Mohave, Chemehuevi, Hopi, and Navajo tribes. The county is also known for its outdoor recreation, particularly along the Colorado River, with popular destinations such as Parker Strip and the Buckskin Mountain State Park. The Quartzsite area is famous for its winter gem shows and RV gatherings, attracting visitors from across the country.
8. Gila County
County Seat: Globe
- Area: 4,795 square miles
- Population: Approximately 53,272 (2020 census)
- Area Codes: 928
- Latitude: 33.3940° N
- Longitude: 110.7933° W
Location and History
Gila County is located in central Arizona and was established on February 8, 1881, from parts of Maricopa and Pinal counties. It is named after the Gila River, which flows through the southern part of the county. Globe, the county seat, developed as a mining town in the late 19th century, primarily for silver and later copper. The county’s history is deeply connected to mining, with significant operations continuing to this day. Gila County is also known for its rugged landscapes, which include parts of the Tonto National Forest and the Mogollon Rim, a significant geological and ecological feature.
Major Highways and Landmarks
Gila County is accessible via U.S. Highways 60 and 70, which provide east-west routes through the region, and State Routes 87 and 260. Significant landmarks include the Tonto National Monument, which preserves ancient cliff dwellings built by the Salado people, and Roosevelt Lake, a major reservoir created by the Theodore Roosevelt Dam, which offers boating, fishing, and camping. The historic Besh-Ba-Gowah Archaeological Park in Globe is another key site, showcasing the ruins of a prehistoric Salado village. The county’s natural beauty and historical significance make it a popular destination for outdoor enthusiasts and history buffs alike.
9. Yavapai County
County Seat: Prescott
- Area: 8,128 square miles
- Population: Approximately 236,209 (2020 census)
- Area Codes: 928
- Latitude: 34.5400° N
- Longitude: 112.4685° W
Location and History
Yavapai County is located in central Arizona and was one of the original counties established on November 8, 1864. It is named after the Yavapai Native American tribe. Prescott, the county seat, was the first capital of the Arizona Territory and has a rich history as a frontier town. The county’s early economy was driven by mining, ranching, and timber, with Prescott becoming a major center for trade and government in the late 19th century. Today, Yavapai County is known for its historical sites, outdoor recreation, and growing arts community, particularly in Prescott and Sedona.
Major Highways and Landmarks
Yavapai County is served by Interstate 17, which runs north-south, connecting Phoenix to Flagstaff, and U.S. Highways 89 and 93. Significant landmarks include the historic Prescott Courthouse Square, a hub of cultural and civic activities, and Montezuma Castle National Monument, an ancient cliff dwelling site. The county is also home to the red rock formations of Sedona, which attract millions of visitors annually for their stunning beauty and spiritual significance. The Verde River and its surrounding wilderness areas provide opportunities for hiking, fishing, and birdwatching. Additionally, the Sharlot Hall Museum in Prescott offers insights into the county’s frontier history.
10. Pinal County
County Seat: Florence
- Area: 5,374 square miles
- Population: Approximately 425,264 (2020 census)
- Area Codes: 520, 480
- Latitude: 32.9185° N
- Longitude: 111.5418° W
Location and History
Pinal County is located in south-central Arizona, between Phoenix and Tucson. It was established on February 1, 1875, from parts of Maricopa and Pima counties. The county is named after the Pinal Mountains, which dominate the landscape. Florence, the county seat, is one of the oldest towns in Arizona, founded in 1866 as a farming and ranching community. The county’s history is linked to the development of agriculture through irrigation, as well as mining, particularly copper. In recent decades, Pinal County has experienced rapid growth due to its proximity to the Phoenix metropolitan area, transforming it into a mix of suburban and rural areas.
Major Highways and Landmarks
Pinal County is intersected by major highways such as Interstate 10, which runs north-south and connects Phoenix to Tucson, and Interstate 8, which provides an east-west route. U.S. Highways 60 and 79 also serve the area. Significant landmarks include the Casa Grande Ruins National Monument, one of the oldest prehistoric structures in North America, and the Superstition Mountains, known for their rugged beauty and the legend of the Lost Dutchman’s Gold Mine. The Boyce Thompson Arboretum, Arizona’s oldest and largest botanical garden, is another key attraction, offering a diverse collection of desert plants from around the world.
List of All Counties in Arizona Alphabetically
Below please see all Arizona counties which are listed in alphabetical order.
- Apache County, AZ
- Cochise County, AZ
- Coconino County, AZ
- Gila County, AZ
- Graham County, AZ
- Greenlee County, AZ
- La Paz County, AZ
- Maricopa County, AZ
- Mohave County, AZ
- Navajo County, AZ
- Pima County, AZ
- Pinal County, AZ
- Santa Cruz County, AZ
- Yavapai County, AZ
- Yuma County, AZ
Map of Arizona Counties
