53,313 people (2024 Census estimate, −0.0% since 2020)
281 square miles of land · 190 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.
11 active community water systems list Boone County in the area they serve, reporting 40,965 people served in all (a system that crosses county lines counts its whole population).
| BELVIDERE groundwater · local government · IL0070050 | 25,339 served |
| AQUA ILLINOIS-CANDLEWICK DVN groundwater · private · IL0075050 | 6,426 served |
| POPLAR GROVE groundwater · local government · IL0070150 | 2,372 served |
| POPLAR GROVE SOUTH groundwater · local government · IL0070300 | 1,877 served |
| FOUR SEASONS MHP buys groundwater · private · IL0075185 | 1,468 served |
| CAPRON groundwater · local government · IL0070100 | 1,343 served |
| POPLAR GROVE WEST-COUNTRYSIDE groundwater · local government · IL0070350 | 790 served |
| GREENVIEW ESTATES MHP buys groundwater · private · IL0070060 | 710 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 46 people were held in Boone County's jail, in Vera's latest figure (2023), or 135 per 100,000 residents ages 15–64. In 2018 it was about 110.
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.
2 school districts have their office in Boone County. School taxes are usually the largest part of a property tax bill.
Spent $154.1 million — $139.6 million to run schools, about $18,474 per student, plus $3.9 million on buildings and equipment. Money in: $67.9 million local (mostly property tax), $86.3 million state, $8.4 million federal. Long-term debt: $60 million.
Spent $34.8 million — $28 million to run schools, about $18,319 per student, plus $2.6 million on buildings and equipment. Money in: $14.5 million local (mostly property tax), $16 million state, $2 million federal. Long-term debt: $11.4 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: Relatively Low compared with other U.S. counties. FEMA estimates natural hazards cost Boone County about $21.4 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.
109 bridges in Boone County: 45 in good condition, 53 fair, and 11 poor (10.1%). “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.
| S. APPLETON ROAD over KISHWAUKEE RIVER · built 1964 | 11,700 vehicles a day |
| LAWRENCEVILLE ROAD over PISCASAW CREEK · built 1974 | 2,050 vehicles a day |
| STONE QUARRY RD over HACKEY CREEK · built 1945 | 1,550 vehicles a day |
| EDSON ROAD over BEAVER CR · built 1973 | 700 vehicles a day |
| COUNTY LINE RD over MUD CREEK · built 1959 | 675 vehicles a day |
| WHEELER RD over CN RR · built 1998 | 200 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $337.7 million of work in Boone County in fiscal 2025, about $6,319 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 Illinois 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 Boone 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 Boone County built: brayden.ozark@gmail.com.
More of Illinois: the state government and every county in Illinois.
Nearby counties: Winnebago County (17 mi) · McHenry County (19 mi) · Rock County, WI (27 mi) · Walworth County, WI (28 mi) · DeKalb County (29 mi) · Ogle County (32 mi).