Portage Township is a charter township of Houghton County in the U.S. state of Michigan. As of the 2000 census, the township population was 3,156. The city of Houghton is adjacent to the north side of the township. Portage Lake is the eastern boundary in the north and the township extends well south of Houghton to the Baraga County line.
There were 1,257 households out of which 28.1% had children under the age of 18 living with them, 53.4% were married couples living together, 6.3% had a female householder with no husband present, and 36.0% were non-families. 26.9% of all households were made up of individuals and 9.8% had someone living alone who was 65 years of age or older. The average household size was 2.49 and the average family size was 3.04.
In the township the population was spread out with 23.7% under the age of 18, 15.2% from 18 to 24, 23.8% from 25 to 44, 24.0% from 45 to 64, and 13.3% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 113.4 males. For every 100 females age 18 and over, there were 112.0 males.
The median income for a household in the township was $33,080, and the median income for a family was $44,213. Males had a median income of $33,958 versus $23,221 for females. The per capita income for the township was $17,655. About 8.1% of families and 14.2% of the population were below the poverty line, including 14.6% of those under age 18 and 8.9% of those age 65 or over.