The median age in Black River Township, Minnesota is 52.8, as per 2021 ACS 5-Year Estimates. Of the total population, 12.90% were under the age of 15, 6.45% aged 15 to 29, 70.97% aged 30 to 64, 9.68% aged 65 to 84, and 0.00% were 85 years of age and older.