108,390 people (2024 Census estimate, −0.9% since 2020)
1,135 square miles of land · 95 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.
37 active community water systems list LaSalle County in the area they serve, reporting 91,992 people served in all (a system that crosses county lines counts its whole population).
| IL AMERICAN-STREATOR surface water · private · IL0995030 | 19,000 served |
| OTTAWA groundwater · local government · IL0990800 | 18,097 served |
| PERU groundwater · local government · IL0990850 | 9,896 served |
| LA SALLE groundwater · local government · IL0990300 | 9,700 served |
| MENDOTA groundwater · local government · IL0990550 | 7,100 served |
| MARSEILLES groundwater · local government · IL0990500 | 5,061 served |
| IL AMERICAN-LAKE HOLIDAY groundwater · private · IL0995200 | 4,750 served |
| OGLESBY groundwater · local government · IL0990700 | 4,500 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 114 people were held in LaSalle County's jail, in Vera's latest figure (2019), or 162 per 100,000 residents ages 15–64. In 2014 it was about 168.
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.
26 school districts have their office in LaSalle County. School taxes are usually the largest part of a property tax bill.
Spent $39.5 million — $31.9 million to run schools, about $18,290 per student, plus $5.9 million on buildings and equipment. Money in: $14.8 million local (mostly property tax), $19.8 million state, $8.8 million federal. Long-term debt: $7.5 million.
Spent $25.5 million — $23 million to run schools, about $14,932 per student, plus $1.7 million on buildings and equipment. Money in: $5.8 million local (mostly property tax), $18.9 million state, $5.1 million federal. Long-term debt: $2.3 million.
Spent $29 million — $24.2 million to run schools, about $19,165 per student, plus $3.2 million on buildings and equipment. Money in: $19.1 million local (mostly property tax), $14.1 million state, $2.5 million federal. Long-term debt: $7.8 million.
Spent $34 million — $30.2 million to run schools, about $25,215 per student, plus $1.3 million on buildings and equipment. Money in: $19.4 million local (mostly property tax), $12.5 million state, $2.2 million federal. Long-term debt: $42 million.
Spent $21.4 million — $14.7 million to run schools, about $14,098 per student, plus $5.3 million on buildings and equipment. Money in: $7.3 million local (mostly property tax), $10 million state, $3.9 million federal. Long-term debt: $3.5 million.
Spent $14.7 million — $13.5 million to run schools, about $14,345 per student, plus $387,000 on buildings and equipment. Money in: $8.6 million local (mostly property tax), $7.1 million state, $2.4 million federal. Long-term debt: $13.1 million.
Spent $20.5 million — $18.2 million to run schools, about $20,355 per student, plus $1.7 million on buildings and equipment. Money in: $3.5 million local (mostly property tax), $12.3 million state, $4.7 million federal. Long-term debt: $5.7 million.
Spent $17.6 million — $15.1 million to run schools, about $18,686 per student, plus $1.7 million on buildings and equipment. Money in: $8.2 million local (mostly property tax), $11.2 million state, $2.6 million federal. Long-term debt: $13.9 million.
And 18 more.
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 Moderate compared with other U.S. counties. FEMA estimates natural hazards cost LaSalle County about $60.5 million a year on average in buildings, crops and lives. Ability to bounce back (community resilience): Very High; social vulnerability: Relatively Low.
Source: FEMA National Risk Index (December 2025), expected annual loss. Ratings compare counties nationwide; they're estimates, not predictions.
528 bridges in LaSalle County: 198 in good condition, 255 fair, and 75 poor (14.2%). “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.
| US 6 FAP 623 over FOX RIVER · built 1928 | 10,700 vehicles a day |
| I-39 SB/US 51SB over C & NW RR · built 1977 | 9,350 vehicles a day |
| ILL 251 (SB) over I 80 · built 1961 | 6,550 vehicles a day |
| ILL 23 FAP 68 over COVEL CREEK · built 1953 | 5,550 vehicles a day |
| ILL 23 FAP 68 over COVEL CREEK · built 1960 | 5,550 vehicles a day |
| ILL 170 over ILL MICH CANAL · built 1940 | 5,550 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $58.1 million of work in LaSalle County in fiscal 2025, about $529 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 LaSalle 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 LaSalle County built: brayden.ozark@gmail.com.
More of Illinois: the state government and every county in Illinois.
Nearby counties: Putnam County (24 mi) · Grundy County (25 mi) · Kendall County (29 mi) · Marshall County (32 mi) · Bureau County (34 mi) · Lee County (35 mi).