Rock River is an unincorporated community on M-28 near the mouth of the Rock River at This is distinct from Rock River Township, which is adjacent to the south of Onota Township. The settlement was a station on the Detroit, Mackinac and Marquette Railroad in 1882 at charcoal kilns near the mouth of the Rock River. A post office was established on February 20, 1886, with John H. Johnson as its first postmaster. The office closed on May 25, 1898, but was restored on October 19, 1898, and continued to operate until June 15, 1906. Various locations along the Rock River have been given this name.
Sand River is an unincorporated community on M-28 near the mouth of the Sand River at The community is on the western boundary of the township and is partially in Chocolay Township in Marquette County. It began as a station on the Detroit, Mackinac and Marquette Railroad in 1882. A post office named Sand River was established in Alger County on March 14, 1891, with Charles A. Hazen as its first postmaster. The office was transferred to Marquette County on September 12, 1908 and closed on December 31, 1911. From 1904 through 1908 it was a winter post office.
Tyoga was a former post office and a station on the Duluth, South Shore and Atlantic Railway at. The settlement formed around the mill and general store of the Tyoga Lumber Company. A post office was established on February 15, 1906, with John W. Bailey as postmaster. The office closed on July 31, 1907. Tyoga now hosts a guided pathway detailing the settlement history of the site.
Geography
According to the United States Census Bureau, the township has a total area of, of which is land and, or 15.31%, is water.
Demographics
As of the census of 2010, there were 352 people, 108 households, and 69 families residing in the township. The population density was 3.6 per square mile. There were 373 housing units at an average density of 4.9 per square mile. The racial makeup of the township was 96.5% White, 2% identified by two or more races, and the remainder as less than 1% of each of the following: Native American, Asian, and Other. There were 108 households out of which 18.5% had children under the age of 18 living with them, 57.4% were married couplesliving together, 5.6% had a female householder with no husband present, and 36.1% were non-families. 30.6% of all households were made up of individuals and 10.2% had someone living alone who was 65 years of age or older. The average household size was 2.04 and the average family size was 2.52. In the township, the population was spread out with 9.9% under the age of 18, 9.1% from 20 to 34, 14.2% from 35 to 49, 37% from 50 to 64, and 29.3% who were 65 years of age or older. There were 184 females, with a median age of 51; and 168 males, with a median age of 54.4. The median income for a household in the township was $37,708, and the median income for a family was $38,333. Males had a median income of $52,000 versus $39,583 for females. The per capita income for the township was $24,267. About 13% of families and 21.6% of the population were below the poverty line, including up to 50% of those under age 18 and 7.7% of those age 65 or over.
