| Official Name: | Rock River Township, Michigan |
| Settlement Type: | Civil township |
| Pushpin Map: | Michigan#USA |
| Pushpin Label: | Rock River Township |
| Pushpin Label Position: | right |
| Pushpin Map Caption: | Location within the state of Michigan##Location within the United States |
| Mapsize: | 250 |
| Subdivision Type: | Country |
| Subdivision Type1: | State |
| Subdivision Type2: | County |
| Subdivision Name2: | Alger |
| Leader Title: | Supervisor |
| Leader Name: | Teri Grout |
| Leader Title1: | Clerk |
| Leader Name1: | Dawn Leppanen |
| Unit Pref: | Imperial |
| Area Total Km2: | 209.8 |
| Area Land Km2: | 209.1 |
| Area Water Km2: | 0.7 |
| Population As Of: | 2020 |
| Population Total: | 1231 |
| Population Density Sq Mi: | 15.0 |
| Timezone: | Eastern (EST) |
| Utc Offset: | -5 |
| Timezone Dst: | EDT |
| Utc Offset Dst: | -4 |
| Elevation M: | 301 |
| Elevation Ft: | 988 |
| Coordinates: | 46.3514°N -86.9656°W |
| Postal Code Type: | ZIP code(s) |
| Postal Code: | 49806 (Au Train) 49816 (Chatham) 49822 (Deerton) 49825 (Eben Junction) 49826 (Rumely) 49885 (Skandia) 49891 (Trenary) |
| Area Code: | 906 |
| Blank Name: | FIPS code |
| Blank Info: | 26-69160[1] |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 1626993 |
Rock River Township is a civil township of Alger County in the U.S. state of Michigan. The population was 1,231 at the 2020 census.[2]
According to the United States Census Bureau, the township has a total area of 209.8km2, of which 209.1km2 is land and 0.7km2, or 0.31%, is water.[3]
In 2000, there were 1,213 people, 505 households, and 363 families residing in the township. The racial makeup of the township was 96.13% White, 1.98% Native American, 0.08% Asian, and 1.81% from two or more races. Among them, 42.2% were of Finnish, 8.1% German, 6.5% French, 6.3% Polish and 5.6% American ancestry. By the publication of the 2020 census, its population grew to 1,231.
In 2000, there were 505 households, out of which 28.3% had children under the age of 18 living with them, 60.2% were married couples living together, 5.9% had a female householder with no husband present, and 28.1% were non-families. 24.0% of all households were made up of individuals, and 10.9% had someone living alone who was 65 years of age or older. The average household size was 2.39 and the average family size was 2.82.
In the township the population was spread out, with 22.3% under the age of 18, 7.9% from 18 to 24, 25.0% from 25 to 44, 30.0% from 45 to 64, and 14.8% who were 65 years of age or older. The median age was 42 years. For every 100 females, there were 102.8 males. For every 100 females age 18 and over, there were 104.3 males.
In 2000, the median income for a household in the township was $32,619, and the median income for a family was $36,750. Males had a median income of $32,132 versus $24,583 for females. The per capita income for the township was $16,360. About 8.1% of families and 10.8% of the population were below the poverty line, including 16.9% of those under age 18 and 11.1% of those age 65 or over. The 2021 census estimates determined the median household income was $54,677.