Maricopa County, AZ
By Michael Liddy on September 13th, 2008
The population explosion is evident in a 2007 Forbes study which ranked four of Maricopa County’s municipalities in the top ten fastest-growing cities in the nation. Those included Buckeye as the 2nd-fastest-growing city, Surprise and Goodyear as 3rd and 4th, respectively, and Avondale as 9th. All four of these cities are located in the booming “West Valley” which is the area of Maricopa County to the west of the City of Phoenix.
There are 12 Indian reservations located in the county. The largest of these are the Salt River Pima Maricopa Indian Community (East of Scottsdale) and the Gila River Indian Community (South of Phoenix), both of which have casino gambling.
Apache Junction (most of Apache Junction is in Pinal County)
Peoria (part of Peoria is in Yavapai County)
Queen Creek (part of Queen Creek is in Pinal County)
 Census-designated places
Sun City West
Check out a 1871 historical description of Maricopa County here: http://www.arizonagenealogy.com/maricopa/