Coconino County: 18,661 square miles.
Maricopa County.
Maricopa county
Maricopa is the largest in population. Coconino County is the largest in area and the County Seat is Flagstaff.
Maricopa.
Catron County on the Arizona border.
The five largest counties by land area in the United States are San Bernardino County (California), Coconino County (Arizona), Nye County (Nevada), Elko County (Nevada), and Mohave County (Arizona).
coconino county with 18,661 sq mi
Coconino with Flagstaff as the county seat.
Catron on the Arizona border.
The second largest county in the lower 48 states is Coconino County in Arizona. It covers an area of about 18,661 square miles.
Maricopa County in Arizona has the highest population in the state. As of the 2020 Census, Maricopa County had a population of over 4.5 million people, making it the most populous county in Arizona. Its county seat is Phoenix, which is also the state capital and largest city in Arizona.
The most populated city is Phoenix. The largest county by area is Coconino.