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.
Lewis and Clark County, Montana, has about 75,000 residents (2024 Census Bureau estimate). A person kept in custody after an arrest in Lewis and Clark County is held at the county jail, run by the Lewis and Clark 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: Lewis and Clark County public records, Lewis and Clark County arrest records, Lewis and Clark County warrants, Lewis and Clark County criminal records, Lewis and Clark County court records, Montana arrest records and Montana inmate search.
Finding Someone in Custody in Lewis and Clark County
The county jail, run by the Lewis and Clark County Sheriff's Office, holds everyone kept in custody after an arrest in Lewis and Clark County, from every agency.
SearchSystems opened and checked the jail page of the Lewis and Clark County Sheriff's Office at lccountymt.gov/Sheriff/Detention-Center (page title: Detention Center | Lewis & Clark County), a site that blocks automated checks (HTTP 403), so open it in a browser.
That page is the office's jail information page rather than a roster.
The Lewis and Clark County Jail by the Numbers
On an average day in 2023 the jail held about 150 people, up from about 130 in 2019. Its rated capacity in 2023 was 166 beds, and it ran at 93 percent of it that year. The figures are from the Vera Institute of Justice's Incarceration Trends data.
Lewis and Clark County has about 75,000 residents (2024 Census Bureau estimate), so the jail holds about 20 people for every 10,000 residents.
Who Books People Into the Lewis and Clark County Jail
The Lewis and Clark County Sheriff's Office and the agencies that report for Helena and East Helena make the arrests that end in a booking in Lewis and Clark County.
The largest arrest counts reported to the FBI were Helena's 1,142 for 2025, the Lewis and Clark County Sheriff's Office's 298 for 2025 and East Helena's 21 for 2025.
Together, the three agencies in Lewis and Clark County with all twelve months of 2025 on file reported 1,461 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 Lewis and Clark County arrest records.
From the Jail to State Prison
The jail holds people awaiting trial and people serving short sentences. A person sentenced to prison in Lewis and Clark County serves the sentence in a facility of the Montana Department of Corrections, whose inmate locator is at offendersearch.mt.gov/conweb.
Frequently Asked Questions
How do I find an inmate in Lewis and Clark County?
Ask the Lewis and Clark County Sheriff's Office; its jail page SearchSystems verified is at lccountymt.gov/Sheriff/Detention-Center.
How many people are in the Lewis and Clark County jail?
About 150 on an average day in 2023, the latest year in the Vera Institute's jail data, against a rated capacity of 166 beds.
Where do people sentenced to prison in Lewis and Clark County go?
To a facility of the Montana Department of Corrections; its inmate locator is at offendersearch.mt.gov/conweb.
Is this the official Lewis and Clark 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.