8,397 people (2024 Census estimate, +5.5% since 2020)
4,564 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 Lemhi County in the area they serve, reporting 3,535 people served in all (a system that crosses county lines counts its whole population).
| SALMON CITY OF surface water · local government · ID7300042 | 3,158 served |
| ELK BEND UNIT 1 groundwater · private · ID7300013 | 200 served |
| SUNSET HEIGHTS WATER DISTRICT groundwater · private · ID7300050 | 65 served |
| VALLEY VIEW HEIGHTS groundwater · private · ID7300057 | 65 served |
| SALMON RIVER MEADOWS MUTUAL WATER COMPAN groundwater · local government · ID7300041 | 47 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 12 people were held in Lemhi County's jail, in Vera's latest figure (2019), or 274 per 100,000 residents ages 15–64. In 2014 it was about 14.
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 Lemhi County. School taxes are usually the largest part of a property tax bill.
Spent $8.2 million — $8.1 million to run schools, about $11,880 per student, plus $65,000 on buildings and equipment. Money in: $1.1 million local (mostly property tax), $5.6 million state, $2.1 million federal.
Spent $2.3 million — $2.1 million to run schools, about $17,333 per student, plus $165,000 on buildings and equipment. Money in: $251,000 local (mostly property tax), $1.9 million state, $484,000 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 Lemhi County about $11.4 million a year on average in buildings, crops and lives. Ability to bounce back (community resilience): Very Low; social vulnerability: Relatively Moderate.
Source: FEMA National Risk Index (December 2025), expected annual loss. Ratings compare counties nationwide; they're estimates, not predictions.
114 bridges in Lemhi County: 65 in good condition, 40 fair, and 9 poor (7.9%). “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 93 over SALMON RIVER;SALMON BR. · built 1926 | 7,300 vehicles a day |
| SALMON RIVER ROAD over PINE CREEK · built 2012 | 350 vehicles a day |
| N. ST. CHARLES over LEMHI RIVER · built 1948 | 310 vehicles a day |
| NO DATA ENTERED over BOULDER CREEK · built 1966 | 200 vehicles a day |
| NO DATA ENTERED over PANTHER CREEK · built 1980 | 200 vehicles a day |
| VIOLA LANE over LEMHI RIVER(BAGLEY BR) · built 1991 | 50 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $2.4 million of work in Lemhi County in fiscal 2025, about $307 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 Idaho 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 Lemhi 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 Lemhi County built: brayden.ozark@gmail.com.
More of Idaho: the state government and every county in Idaho.
Nearby counties: Custer County (49 mi) · Beaverhead County, MT (51 mi) · Ravalli County, MT (80 mi) · Valley County (85 mi) · Clark County (87 mi) · Deer Lodge County, MT (88 mi).