Tunnel City is an unincorporated 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...

 in the town of Greenfield

Greenfield, Monroe County, Wisconsin

Greenfield is a town in Monroe County, Wisconsin, United States. The population was 626 at the 2000 census. The unincorporated community of Tunnel City is located within the town.-Geography:...

, in Monroe County, Wisconsin

Monroe County, Wisconsin

Monroe County is a county in the U.S. state of Wisconsin. As of 2000, the population was 40,899. Its county seat is Sparta.-Geography:According to the U.S...

, United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, named for the train tunnel just to the west which was used by the Chicago and North Western Railway

Chicago and North Western Railway

The Chicago and North Western Transportation Company was a Class I railroad in the Midwest United States. It was also known as the North Western. The railroad operated more than of track as of the turn of the 20th century, and over of track in seven states before retrenchment in the late 1970s...

 (trackage now abandoned west of the tunnel) and the Chicago, Milwaukee, St. Paul & Pacific Railroad (Milwaukee Road). The existing track is owned by the Canadian Pacific Railway

Canadian Pacific Railway

The Canadian Pacific Railway , formerly also known as CP Rail between 1968 and 1996, is a historic Canadian Class I railway founded in 1881 and now operated by Canadian Pacific Railway Limited, which began operations as legal owner in a corporate restructuring in 2001...

, and carries the Amtrak Empire Builder

Empire Builder

The Empire Builder is a passenger train route operated by Amtrak in the Midwestern and Northwestern United States. It is Amtrak's busiest long-distance route and busiest daily train, carrying more than 500,000 travelers annually since 2007. Overall, it is the railroad's 10th-busiest line. Before...

passenger train, though rail traffic is dominated by freight. As of the 2010 census

United States Census, 2010

The Twenty-third United States Census, known as Census 2010 or the 2010 Census, is the current national census of the United States. National Census Day was April 1, 2010 and is the reference date used in enumerating individuals...

, its population is 106. Tunnel City has an area of 0.31 mi2, all of it land.