Portage township
- County:
- Brown County
- County Seat:
- No
- Area (mi²):
- 35.652
- State:
- South Dakota
Portage township is located in Brown County, South Dakota. Portage township has a 2026 population of 35. Portage township is currently declining at a rate of -2.78% annually and its population has decreased by -5.41% since the most recent census, which recorded a population of 37 in 2020.