Surprise Valley township Flag

Surprise Valley township

County:
Mellette County
County Seat:
No
Area (mi²):
33.505
State:
South Dakota

Surprise Valley township is located in Mellette County, South Dakota. Surprise Valley township has a 2026 population of 19. Surprise Valley township is currently growing at a rate of 5.56% annually and its population has increased by 35.71% since the most recent census, which recorded a population of 14 in 2020.

The median age in Surprise Valley township is 72.3 years: 0 years for males, and 0 years for females. For every 100 females there are 127.3 males.

19
Total Population
0.57
Density (mi²)
1 5.56%
Growth

Surprise Valley township Population

Surprise Valley township Population

Year ↓
Population
Growth
Annual Change
20261915.56%
20251815.88%
20241716.25%
20231600%
20221600%
202116214.29%
20201400%
20192400%
201824-1-4%
20172500%
20162514.17%
201524-1-4%
20142500%
20132500%
20122500%
20112500%
20102500%

Median Age

Overall: 72.3 years
Female: 0 years
Male: 0 years

Surprise Valley township Adults

There are 50 adults, (36 of whom are seniors) in Surprise Valley township.

Sex Ratio

Female: 22 (44%)
Male: 28 (56%)

Demographics

The racial composition of Surprise Valley township includes 100% White, and smaller percentages for and multiracial populations.

Population by Race

Race
Population ↓
Percentage (of total)
White50100%
Race
Population ↓
Percentage (of total)
White50100%

Surprise Valley township Marital Status

Sources

  1. US Census State Population Estimates - Most recent state estimates from the Census Bureau's Population Estimates Program
  2. US Census County Population Estimates - Most recent county estimates from the Census Bureau's Population Estimates Program
  3. American Community Survey (2009 - 2013)
  4. Census QuickFacts
  5. Historical Populations of States and Counties (1790 - 1990)