Irwin is an unincorporated community

Unincorporated area

In law, an unincorporated area is a region of land that is not a part of any municipality.To "incorporate" in this context means to form a municipal corporation, a city, town, or village with its own government. An unincorporated community is usually not subject to or taxed by a municipal government...

 in Merced County

Merced County, California

Merced County , is a county located in the Central Valley of the U.S. state of California, north of Fresno and southeast of San Jose. As of the 2010 census, the population was 255,793, up from 210,554 at the 2000 census. The county seat is Merced...

, California

California

California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

. It is located 4.5 miles (7.2 km) west-northwest of Delhi

Delhi, California

Delhi is a census-designated place in Merced County, California, USA. Delhi is located west-northwest of Merced, at an elevation of 118 feet...

 and about 1 miles (1.6 km) south of Hilmar

Hilmar, California

Hilmar-Irwin is a census-designated place in Merced County, California, United States. The population was 5,197 at the 2010 census, up from 4,807 at the 2000 census.-Geography:...

, at an elevation of 98 feet (30 m). For census purposes, Irwin is aggregated with nearby communities in the census-designated place

Census-designated place

A census-designated place is a concentration of population identified by the United States Census Bureau for statistical purposes. CDPs are delineated for each decennial census as the statistical counterparts of incorporated places such as cities, towns and villages...

 Hilmar-Irwin, California.

A post office operated at Irwin from 1911 to 1958. The name honors W.A. Irwin, founder of the town.