115,979 people (2024 Census estimate, +5.8% since 2020)
2,777 square miles of land · 42 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.
67 active community water systems list Pennington County in the area they serve, reporting 121,343 people served in all (a system that crosses county lines counts its whole population).
| RAPID CITY surface water · local government · SD4600406 | 72,009 served |
| BOX ELDER groundwater · local government · SD4600046 | 14,000 served |
| RAPID VALLEY SANITARY DISTRICT surface water · local government · SD4600274 | 11,408 served |
| ELLSWORTH AFB buys surface water · federal · SD4680004 | 9,100 served |
| COLONIAL PINE HILLS SANITARY DISTRIC groundwater · local government · SD4600263 | 1,200 served |
| CHAPEL LANE WATER COMPANY groundwater · private · SD4600264 | 1,200 served |
| WR/LJ - CREIGHTON PROJECT groundwater · private · SD4602156 | 1,170 served |
| NORTHDALE SANITARY DISTRICT groundwater · local government · SD4600514 | 1,075 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 632 people were held in Pennington County's jail, in Vera's latest figure (2023), or 888 per 100,000 residents ages 15–64. In 2018 it was about 1,300.
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.
5 school districts have their office in Pennington County. School taxes are usually the largest part of a property tax bill.
Spent $165 million — $133 million to run schools, about $10,432 per student, plus $29.8 million on buildings and equipment. Money in: $95.1 million local (mostly property tax), $45.5 million state, $40.8 million federal. Long-term debt: $64.1 million.
Spent $33.5 million — $31.9 million to run schools, about $11,613 per student, plus $1.6 million on buildings and equipment. Money in: $8.3 million local (mostly property tax), $17.1 million state, $9.9 million federal. Long-term debt: $135,000.
Spent $6.9 million — $6.1 million to run schools, about $12,450 per student, plus $705,000 on buildings and equipment. Money in: $7.2 million local (mostly property tax), $246,000 state, $1.4 million federal. Long-term debt: $1.3 million.
Spent $4.9 million — $3.2 million to run schools, about $11,007 per student, plus $1.7 million on buildings and equipment. Money in: $1.4 million local (mostly property tax), $1.9 million state, $1 million federal. Long-term debt: $15,000.
Spent $4.4 million — $4.2 million to run schools, about $14,777 per student, plus $207,000 on buildings and equipment. Money in: $2.2 million local (mostly property tax), $1.4 million state, $1.1 million federal. Long-term debt: $103,000.
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: Relatively Low compared with other U.S. counties. FEMA estimates natural hazards cost Pennington County about $40.8 million a year on average in buildings, crops and lives. Ability to bounce back (community resilience): Relatively High; social vulnerability: Relatively Low.
Source: FEMA National Risk Index (December 2025), expected annual loss. Ratings compare counties nationwide; they're estimates, not predictions.
348 bridges in Pennington County: 121 in good condition, 206 fair, and 21 poor (6.0%). “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.
| CHAPEL LANE over RAPID CK · built 1974 | 4,700 vehicles a day |
| US385 over HORSE CK · built 1947 | 2,378 vehicles a day |
| COUNTRY ROAD over BOX ELDER CK · built 1950 | 1,214 vehicles a day |
| TOWN STREET (US16) over ABANDON LINE RR · built 1930 | 1,000 vehicles a day |
| BENNET ROAD over BOX ELDER CK · built 1973 | 881 vehicles a day |
| ELM AVENUE over DRAINAGE DITCH · built 1984 | 300 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $186.1 million of work in Pennington County in fiscal 2025, about $1,704 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 Pennington 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 Pennington County built: brayden.ozark@gmail.com.
More of South Dakota: the state government and every county in South Dakota.
Nearby counties: Custer County (39 mi) · Meade County (42 mi) · Oglala Lakota County (48 mi) · Lawrence County (54 mi) · Jackson County (64 mi) · Fall River County (64 mi).