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 on September 24, 2026.
Sanders County, Montana, has about 14,000 residents (2024 Census Bureau estimate). A person kept in custody after an arrest in Sanders County is held at the county jail, run by the Sanders County Sheriff's Office, and the jail's record of each person held is a public record. This guide says where to look for someone in custody, what the jail holds and who books people into it.
This guide covers the search, the jail, who books people, state prison and common questions.
Related guides: Sanders County public records, Sanders County arrest records, Sanders County warrants, Sanders County criminal records, Sanders County court records, Montana arrest records and Montana inmate search.
Finding Someone in Custody in Sanders County
The county jail, run by the Sanders County Sheriff's Office, holds everyone kept in custody after an arrest in Sanders County, from every agency.
SearchSystems opened and checked the jail page of the Sanders County Sheriff's Office at co.sanders.mt.us/212/Sheriffs-Office (page title: Sheriff's Office | Sanders County, MT), phone 406-203-0082, 1115 Main Street Thompson Falls, MT 59873, Monday through Friday 8 am to 5 pm, which answered when SearchSystems opened it on September 24, 2026.
That page is the office's jail information page rather than a roster, so a search for a particular person goes through the office at 406-203-0082.
The Sanders County Jail by the Numbers
On an average day in 2019 the jail held about 27 people. Its rated capacity in 2019 was 29 beds, and it ran at 93 percent of it that year. The figures are from the Vera Institute of Justice's Incarceration Trends data.
Sanders County has about 14,000 residents (2024 Census Bureau estimate), so the jail holds about 19 people for every 10,000 residents.
Who Books People Into the Sanders County Jail
The Sanders County Sheriff's Office and the agencies that report for Thompson Falls, Plains and Hot Springs make the arrests that end in a booking in Sanders County.
The largest arrest counts reported to the FBI were the Sanders County Sheriff's Office's 17 for 2025, Thompson Falls's 7 for 2025 and Hot Springs's 0 for 2025.
Together, the four agencies in Sanders County with all twelve months of 2025 on file reported 24 arrests to the FBI that year. Those kept in custody were booked into the county jail; a person cited and released at the scene was not.
The counts, agency by agency and year by year, are in Sanders County arrest records.
From the Jail to State Prison
A sentence of more than a year is served in state prison, not the jail; the Montana Department of Corrections lists its inmates at offendersearch.mt.gov/conweb.
Frequently Asked Questions
How do I find an inmate in Sanders County?
Ask the Sanders County Sheriff's Office at 406-203-0082; its jail page SearchSystems verified is at co.sanders.mt.us/212/Sheriffs-Office.
How many people are in the Sanders County jail?
About 27 on an average day in 2019, the latest year in the Vera Institute's jail data, against a rated capacity of 29 beds.
What is the phone number for the Sanders County jail?
406-203-0082, the number on the page of the Sanders County Sheriff's Office SearchSystems verified.
Where do people sentenced to prison in Sanders County go?
To a facility of the Montana Department of Corrections; its inmate locator is at offendersearch.mt.gov/conweb.
Is this the official Sanders 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.