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 2, 2026.
Cascade County, Montana, has about 85,000 residents (2024 Census Bureau estimate). A person kept in custody after an arrest in Cascade County is held at the county jail, run by the Cascade 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: Cascade County public records, Cascade County arrest records, Cascade County warrants, Cascade County criminal records, Cascade County court records, Montana arrest records and Montana inmate search.
Finding Someone in Custody in Cascade County
A person kept in custody after an arrest in Cascade County is held at the county jail, run by the Cascade County Sheriff's Office, whichever agency made the arrest.
SearchSystems opened and checked the custody page of the Cascade County Sheriff's Office at cascadecountymt.gov/314/Inmate-Roster (page title: Inmate Roster | Cascade County, MT), phone 406-454-6820, which answered when SearchSystems opened it on September 24, 2026.
That page is the place to look for someone 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.
The Cascade County Jail by the Numbers
On an average day in 2023 the jail held about 430 people, down from about 470 in 2019. Its rated capacity in 2023 was 365 beds, and it ran at 117 percent of it that year. The figures are from the Vera Institute of Justice's Incarceration Trends data.
Cascade County has about 85,000 residents (2024 Census Bureau estimate), so the jail holds about 50 people for every 10,000 residents.
Who Books People Into the Cascade County Jail
The Cascade County Sheriff's Office and the agency that reports for Great Falls make the arrests that end in a booking in Cascade County.
The FBI's agency list also places one more agency in Cascade County: the Great Falls International Airport Authority (other agency).
The largest arrest counts reported to the FBI were Great Falls's 3,013 for 2025 and the Cascade County Sheriff's Office's 589 for 2025.
Together, the two agencies in Cascade County with all twelve months of 2025 on file reported 3,602 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 Cascade 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 Cascade County?
Look on the custody page of the Cascade County Sheriff's Office at cascadecountymt.gov/314/Inmate-Roster, or call 406-454-6820. It covers people booked into the county jail.
How many people are in the Cascade County jail?
About 430 on an average day in 2023, the latest year in the Vera Institute's jail data, against a rated capacity of 365 beds.
What is the phone number for the Cascade County jail?
406-454-6820, the number on the page of the Cascade County Sheriff's Office SearchSystems verified.
Where do people sentenced to prison in Cascade County go?
To a facility of the Montana Department of Corrections; its inmate locator is at offendersearch.mt.gov/conweb.
Is this the official Cascade 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.