3,721 people (2024 Census estimate, +0.5% since 2020)
1,642 square miles of land · 2 people per square mile
“Highest” and “lowest” are just order, not grades: a high rank for poverty or hazard losses means more of it. Each figure's source is in its section below.
5 active community water systems list Lyman County in the area they serve, reporting 11,173 people served in all (a system that crosses county lines counts its whole population).
| WR/LJ - MNI WICONI buys surface water · private · SD4602223 | 5,185 served |
| TRIPP COUNTY WATER USER DISTRICT groundwater · local government · SD4600520 | 4,860 served |
| PRESHO buys surface water · local government · SD4600248 | 472 served |
| OACOMA surface water · local government · SD4600229 | 391 served |
| KENNEBEC buys surface water · local government · SD4600182 | 265 served |
Source: U.S. EPA Safe Drinking Water Information System (SDWIS), active community systems, . Look up any system's violations and test results with EPA's search using its ID.
About 2 people were held in Lyman County's jail, in Vera's latest figure (1970), or 88 per 100,000 residents ages 15–64.
Source: Vera Institute of Justice, Incarceration Trends (built from federal Bureau of Justice Statistics jail surveys). Counties without their own jail, or that share one, may show no figure.
1 school district has its office in Lyman County. School taxes are usually the largest part of a property tax bill.
Spent $6.5 million — $5.7 million to run schools, about $15,527 per student, plus $723,000 on buildings and equipment. Money in: $3.5 million local (mostly property tax), $1.3 million state, $2.6 million federal. Long-term debt: $2.3 million.
Source: U.S. Census Bureau, 2023 Annual Survey of School System Finances. Districts are listed by the county of their main office; some serve neighboring counties too.
Source: County Health Rankings & Roadmaps 2025 (University of Wisconsin Population Health Institute), which gathers federal data (CDC, Census, and others); measures cover different recent years. Blank lines aren't reported for small counties.
Overall risk: Very Low compared with other U.S. counties. FEMA estimates natural hazards cost Lyman County about $5.9 million a year on average in buildings, crops and lives. Ability to bounce back (community resilience): Relatively Low; social vulnerability: Very High.
Source: FEMA National Risk Index (December 2025), expected annual loss. Ratings compare counties nationwide; they're estimates, not predictions.
114 bridges in Lyman County: 46 in good condition, 56 fair, and 12 poor (10.5%). “Poor” means a main part — the deck, the beams, or the supports — is rated 4 or lower on the federal 0–9 scale. It doesn't mean unsafe to drive; unsafe bridges are closed.
| I090 WF over R&W RR · built 1953 | 2,622 vehicles a day |
| IRR BIA RTE 5 over COUNSELOR CREEK · built 1965 | 663 vehicles a day |
| 241ST STREET over MEDICINE CREEK · built 1930 | 55 vehicles a day |
| 241ST STREET over TRIB. TO MEDICINE CREEK · built 1930 | 45 vehicles a day |
| 318TH AVENUE over CREEK · built 1930 | 24 vehicles a day |
| RIVER ROAD over CREEK · built 1965 | 16 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $15 million of work in Lyman County in fiscal 2025, about $4,046 per resident — to the county, cities, schools, hospitals, nonprofits and others.
Source: USAspending.gov, grants by place of performance, fiscal 2025 (Oct. 2024 to Sept. 2025). Search it by county to see each award.
From Grants.gov: posted grants listing county governments as eligible, soonest deadline first; research-only and overseas programs left out; list updated 2026-10-13, refreshed weekly. 62 are open in all. Cities, towns, school districts and nonprofits have their own lists there.
Registration deadlines, early voting and polling places for South Dakota are on the federal site vote.gov, which links to the state's official election office.
The budget, property tax rates, audits, local officials and offices for Lyman County come from the county's own records, which we haven't gathered — not gathered, never hidden. See what a full county site looks like, or ask to have Lyman County built: brayden.ozark@gmail.com.
More of South Dakota: the state government and every county in South Dakota.
Nearby counties: Buffalo County (33 mi) · Hughes County (34 mi) · Tripp County (38 mi) · Brule County (39 mi) · Jones County (42 mi) · Hyde County (48 mi).