When was Maricopa County founded?

Maricopa County was founded in 1871, formed from Yavapai County, and named after Maricopa people.

What is the county seat of Maricopa County?

The county seat of Maricopa County is Phoenix.

Is there an online parcel map for Maricopa County?

Yes. Maricopa County publishes a parcel map of 1,761,058 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.

Has Maricopa County's boundary or name changed?

Maricopa County was created in 1871 from Yavapai County. Since then the Atlas of Historical County Boundaries records 4 later changes, chiefly involving Pima County, Gila County and Pinal County.

Is my lot in a flood zone?

We do not have flood maps for Maricopa County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

County · code 04013

Maricopa CountyArizona

Maricopa County is in Arizona with its county seat in Phoenix. It was created on February 14, 1871, and is named after the Maricopa people.

Founded1871
County seatPhoenix
Named forMaricopa people
Land area9,202 sq mi + 24 sq mi water
Population4,420,568 2020 Census
Parcels mapped1,761,058 checked 16 October 2026

Open the free map Click any parcel in Maricopa County: acreage, parcel id, address and who publishes the map. No sign-in.

Updated 19 October 2026

Census outline · seat marked

Where it is

Maricopa on the map of Arizona

Arizona has 15 counties and county equivalents, each with its own records office. Shapes with a page are links.

Counties of Arizona · Maricopa highlighted

History

Formed in 1871 from Yavapai County

An old deed may name a county that no longer exists, or a boundary that has since moved.

Maricopa County was created by Arizona Territory from Yavapai County. The county gained territory from Pima County in 1873, lost territory to the creation of Pinal County in 1875, and gained and lost small areas from Yavapai and Pima counties in 1877. In 1881, Maricopa lost territory to the creation of Gila County.

Boundary changes from the Newberry Library, Atlas of Historical County Boundaries.

1871
Maricopa County created Maricopa created by Arizona Territory from Yavapai.
from Yavapai
14 February 1871 · Ariz. Terr. Laws 1871, 6th assy./ pp. 53-54
1873
Gained territory Maricopa gained from Pima.
from Pima
14 February 1873 · Ariz. Terr. Laws 1873, 7th assy./ p. 87
1875
Lost territory Maricopa lost to creation of Pinal.
to Pinal
1 February 1875 · Ariz. Terr. Laws 1875, 8th assy./ pp. 19-20
1877
Gained territory Maricopa gained from Yavapai, and lost small area along the Gila River to Pima.
from Yavapai from Pima
31 January 1877 · Ariz. Terr. Laws 1877, 9th assy./ pp. 12-13
1881
Lost territory Maricopa lost to creation of Gila.
to Gila
8 February 1881 · Ariz. Terr. Laws 1881, 11th assy./ pp. 14-17

Land and parcels

What the maps cover in Maricopa

Who publishes each layer, how good it is, and when we last checked.

Parcels Good enough

Lot lines and tax-map numbers for 1,761,058 parcels from Maricopa County. Drawn for tax purposes: usually within a few feet of a survey, but not a survey.
edited 16 October 2026 · checked 16 October 2026
Address points Missing

No public address points layer found for Maricopa County yet.
Buildings Reference

Roof outlines traced from aerial imagery from FEMA Response Geospatial Office with Oak Ridge National Laboratory (ORNL). Good for seeing what is on a lot; not accurate enough to set a fence from.
checked 18 October 2026

Official: from the office that keeps the record
Good enough: a reliable statewide or national copy
Fallback: a guide only; check the official record
Missing: nothing public found yet

People and land

Maricopa by the Census

Population

4,420,568 2020 Census count

Housing units

1,812,827 2020 Census count

Land area

9,202 square miles

Water area

24 square miles

People per sq mi

480 population ÷ land area

Source: US Census Bureau, 2020 Census; US Census Bureau, 2020 Gazetteer Files. Not endorsed or certified by the Census Bureau.

See your own lot on these maps

Open Maricopa County on Parcel Chart's free map and click your parcel. Save it with a free account; the full record of your place (site map, projects, documents) is Pro, in early access.

Open the free map no sign-in Pro early access

Questions

Common questions about Maricopa County

When was Maricopa County founded?: Maricopa County was founded in 1871, formed from Yavapai County, and named after Maricopa people.
What is the county seat of Maricopa County?: The county seat of Maricopa County is Phoenix.
Is there an online parcel map for Maricopa County?: Yes. Maricopa County publishes a parcel map of 1,761,058 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
Has Maricopa County's boundary or name changed?: Maricopa County was created in 1871 from Yavapai County. Since then the Atlas of Historical County Boundaries records 4 later changes, chiefly involving Pima County, Gila County and Pinal County.
Is my lot in a flood zone?: We do not have flood maps for Maricopa County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

Nearby