1,834 people (2024 Census estimate, −4.6% since 2020)
1,307 square miles of land · 1 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.
2 active community water systems list Mellette County in the area they serve, reporting 5,393 people served in all (a system that crosses county lines counts its whole population).
| TRIPP COUNTY WATER USER DISTRICT groundwater · local government · SD4600520 | 4,860 served |
| WHITE RIVER buys surface water · local government · SD4600367 | 533 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 14 people were held in Mellette County's jail, in Vera's latest figure (2019), or 1,206 per 100,000 residents ages 15–64. In 2014 it was about 9.
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 Mellette County. School taxes are usually the largest part of a property tax bill.
Spent $8.5 million — $7.3 million to run schools, about $17,516 per student, plus $1.1 million on buildings and equipment. Money in: $2.7 million local (mostly property tax), $2.8 million state, $3.9 million federal.
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 Mellette County about $1.9 million a year on average in buildings, crops and lives. Ability to bounce back (community resilience): Very Low; social vulnerability: Very High.
Source: FEMA National Risk Index (December 2025), expected annual loss. Ratings compare counties nationwide; they're estimates, not predictions.
28 bridges in Mellette County: 9 in good condition, 17 fair, and 2 poor (7.1%). “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.
| PINE CREEK (UNORG) over PINE CK · built 1992 | 10 vehicles a day |
| COUNTY HIGHWAY #7 over COTTONWOOD CK · built 1982 | 9 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $20.8 million of work in Mellette County in fiscal 2025, about $10,836 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 Mellette 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 Mellette County built: brayden.ozark@gmail.com.
More of South Dakota: the state government and every county in South Dakota.
Nearby counties: Jones County (26 mi) · Todd County (26 mi) · Jackson County (44 mi) · Tripp County (47 mi) · Lyman County (51 mi) · Bennett County (54 mi).