How many people live in Lyman County, SD?
Updated Apr. 6, 2026Refreshed annually
In 2024, there were about 3,700 people living in Lyman County, SD. That makes Lyman County the 43rd-most populous county in South Dakota. It is home to 0.4% of people living in the state.
3.72K
population of Lyman County, SD (2024)
0.4%
County share of the South Dakota population (2024)
About 3,700 people lived in Lyman County, SD in 2024.
Population estimates, 2000–2024
What are Lyman County, SD’s age demographics?
About 703 Lyman County residents are aged 65 and older in 2024. That represents 18.9% of its population. For comparison, the age group represents 18.9% of South Dakota’s population and 18% in the US overall.
Another 1,000 Lyman County residents, or 27.4% of the population, were children under 18. For comparison, the age group represents 24% of South Dakota’s population and 21.6% in the US overall.
A higher share of Lyman County, SD's population is aged under 18 than the US as a whole.
Population estimates by age group, (2024)
What are Lyman County, SD’s racial and ethnic demographics?
Non-Hispanic American Indian and Alaska Native residents make up 37.4% of the Lyman County population, higher than the national share of 0.72%. Lyman County also has a larger share of people identifying as non-Hispanic two or more races (3.1%) than the US overall (2.5%).
In contrast, Lyman County’s Hispanic population accounts for 1.5%, below the 20% nationwide, and the non-Hispanic Black or African American population makes up 0.67% of the county, compared with 12.6% nationally.
Racial and ethnic make up differ based on location. These figures reflect how people identified their race alone (not in combination with other races), and separate out Hispanic or Latino ethnicity, following Census reporting standards.
Lyman County, SD has a higher share of a non-Hispanic American Indian and Alaska Native population than South Dakota as a whole.
Population estimates by race and ethnicity, (2024)
The largest city or town in Lyman County, SD is Lower Brule UT with about 1,600 residents in 2024.
Cities and towns in Lyman County, SD ranked by population
Population (2024), includes only portions within county
| City or town | Population | |
|---|---|---|
| 1. | Lower Brule UT | 1,618 |
| 2. | Presho | 467 |
| 3. | Oacoma | 392 |
| 4. | Kennebec | 285 |
| 5. | West Lyman UT | 220 |
| 6. | East Lyman UT | 148 |
| 7. | Reliance | 127 |
| 8. | Vivian | 125 |
| 9. | Central Lyman UT | 119 |
| 10. | Oacoma | 81 |
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Methodology
USAFacts standardizes data, in areas such as time and demographics, to make it easier to understand and compare.
The analysis was generated with the help of AI and reviewed by USAFacts for accuracy.
Page sources
USAFacts endeavors to share the most up-to-date information available. We sourced the data on this page directly from government agencies; however, the intervals at which agencies publish updated data vary.
