Reviewed and updated October 9, 2026 by the SearchSystems.net editorial team. The arrest counts are the ones each agency reported to the FBI, as the FBI held them on October 8, 2026. The jail figures are from the Vera Institute of Justice's Incarceration Trends data. Every office link was opened and checked against the office's own site between September 24, 2026 and October 4, 2026.
Lake County, Montana, has about 33,000 residents (2024 Census Bureau estimate), and arrests there are reported to the FBI by the Lake County Sheriff's Office and three city agencies. An arrest leaves the same records whoever makes it: the arresting agency's report, the record of anyone held at the county jail, and, if the County Attorney files charges, a case in the Lake County District Court. This guide says who keeps each one, what it costs and who may see it, with the arrest counts each agency reported.
This guide covers who makes arrests, how many arrests, booking and the jail, finding an arrest, copies, cities and common questions.
Related guides: Lake County public records, Montana arrest records, Montana inmate search and Montana criminal records.
Who Makes Arrests in Lake County
The Lake County Sheriff's Office is the county agency that reports arrests to the FBI for Lake County. It reported 323 arrests for 2025.
Arrests inside three of the county's cities are reported to the FBI by an agency of the city's own, listed here with the Census population and what each reported:
- Polson, 5,631 residents: 299 arrests reported for 2025.
- Ronan, 2,182 residents: 99 arrests reported for 2025.
- St. Ignatius, 830 residents: 0 arrests reported for 2025.
A city on that list is reported separately whether the officers are the city's own or the sheriff's under contract; the FBI's list does not say which.
How Many Arrests Each Agency Reports in Lake County
Each agency reports its arrests to the FBI by month, and the FBI publishes them on the Crime Data Explorer. These are the full-year totals, all offenses, as the FBI held them on October 8, 2026; a year with months missing or not reported is left out.
- Lake County Sheriff's Office: 323 for 2025, 271 for 2024, 370 for 2023, 414 for 2022, 464 for 2021 and 434 for 2020.
- Polson: 299 for 2025, 338 for 2024, 296 for 2023, 404 for 2022, 430 for 2021 and 384 for 2020.
- Ronan: 99 for 2025, 72 for 2024, 104 for 2023, 95 for 2022, 124 for 2021 and 137 for 2020.
- St. Ignatius: 0 for 2025, 0 for 2024, 2 for 2023, 20 for 2022 and 9 for 2021.
Together, the four agencies with all twelve months of 2025 on file reported 721 arrests that year. The same agencies with both 2025 and 2024 complete reported 721 in 2025 against 681 in 2024, up 5.9 percent.
Through August 2026, the four agencies with every month so far on file reported 361 arrests, against 494 in the same months of 2025.
Booking: Where People Arrested in Lake County Are Held
The county jail is where a person arrested in Lake County and kept in custody ends up, whichever agency made the arrest, though a city department may hold someone in its own cells first and a person cited and released at the scene is never booked. The jail's record of each person held, with the charges, is a public record of the arrest, and once the person is released or sentenced the record continues in the court file.
On an average day in 2021 the jail held about 41 people, down from about 54 in 2019. Its rated capacity in 2019, the last year with a capacity figure, was 42 beds, and it ran at 129 percent of it that year. The figures are from the Vera Institute of Justice's Incarceration Trends data.
SearchSystems opened and checked the custody page of the Lake County Sheriff's Office at roster.assurances.gov.gh/lake-county-montana-jail-roster.html (page title: Lake County Montana Jail Roster), which answered when SearchSystems opened it on October 4, 2026.
That page is the place to look for someone who was booked recently; a person cited and released at the scene, or held only a few hours by a city department, will not be on it.
A sentence of more than a year is served in state prison; the Montana Department of Corrections lists its inmates at offendersearch.mt.gov/conweb.
How to Find Out About an Arrest in Lake County
An arrest in Lake County can be traced in three places, depending on where the case stands: the custody page of the Lake County Sheriff's Office described above, for anyone booked into the county jail; the case index of the Lake County District Court, which shows whether charges were filed and the next court date (the court records page SearchSystems verified is at courts.mt.gov); the County Attorney, which decides whether an arrest becomes a charge (its page is at lakemt.gov/368/County-Attorneys-Office, phone 406-883-7279).
Montana is one of the states that lets anyone look up another person's statewide criminal history: the CHOPRS service lets anyone search public criminal history online by name, through the Montana Department of Justice. That record shows what agencies reported to the state, which is wider than one county's court index but can lag it.
Getting a Copy of an Arrest Record in Lake County
The report of an arrest is released by the agency that made it; the jail and the court hold their own records of the same event, but not the report. Under the Montana Public Records Act the agency must answer in a timely manner; the statute sets no number of days, and it may charge the actual cost of fulfilling the request.
- An arrest by the Lake County Sheriff's Office: ask its records unit.
- An arrest in Polson, Ronan or St. Ignatius: the records unit of the agency that reports for that city.
- A defendant who has been charged gets the report through the case: the County Attorney, 406-883-7279, handles discovery for pending cases.
- The court file of a case that was filed: the Lake County District Court, through the court records page at courts.mt.gov.
- Your own statewide record: the same request described above, for your own name.
Cities in Lake County: Who Reports the Arrests
The FBI lists a separate arrest reporting agency for every one of the three cities in Lake County: Polson, Ronan and St. Ignatius.
Wherever in the county the arrest happens, a person kept in custody goes to the county jail and the case goes to the Lake County District Court.
Frequently Asked Questions
How many arrests are made in Lake County each year?
The Lake County Sheriff's Office reported 323 arrests to the FBI for 2025, and the four agencies with every month of 2025 on file reported 721 between them.
How do I find out if someone is in jail in Lake County?
Look on the custody page of the Lake County Sheriff's Office at roster.assurances.gov.gh. It covers people booked into the county jail.
Where are people arrested in Lake County booked?
Those kept in custody go to the county jail, run by the Lake County Sheriff's Office; a person cited and released at the scene is not booked.
Are arrest records public in Lake County?
The court files of criminal cases are public, and so is the statewide criminal history kept by the Montana Department of Justice: the CHOPRS service lets anyone search public criminal history online by name. The arrest report itself is released by the agency that made the arrest, under the Montana Public Records Act.
How do I get a copy of an arrest report in Lake County?
From the agency that made the arrest: the Lake County Sheriff's Office for its own arrests, or the agency that reports for the city where it happened. Under the Montana Public Records Act the answer is due in a timely manner; the statute sets no number of days.
Is this the official Lake County website?
No. SearchSystems.net is an independent public records guide, online since 1997. It links to the official county, court and state offices described above and does not hold records, charge for them or take requests.