Yellowstone County Jail & Inmate Roster
Custody for arrests in Yellowstone County sits with the county, not with any city within it. The the county jail holds people through trial, and the sheriff's office is the agency that can confirm whether someone is there.
Yellowstone County jail and sheriff
| County | Yellowstone County |
|---|---|
| Population | 171,583 (2024) |
Where a field is blank, the county does not publish that detail on an official source we can cite.
How to find someone in the county jail
- Have their date of birth ready — it is the detail that separates people with common names.
- If the charge is federal, search the Bureau of Prisons system, which is separate from both.
- Call the jail directly if the name does not appear; online rosters lag behind actual bookings.
- Search the county's official roster for the person's full legal name.
- If the person has already been sentenced, search the Montana Department of Corrections offender locator instead.
Cities in Yellowstone County
1 city in Yellowstone County is covered, each with its own inmate search and bail information.
The Montana state prison system
Sentenced prisoners in Montana are held by the Montana Department of Corrections, not by Yellowstone County. A person stops appearing on the county roster once transferred.
How the Yellowstone County jail system works
Yellowstone County is the facility that takes bookings for arrests in Montana. County jails are short-stay by design: people move through them to court, to release, or on to a state prison. That turnover is why a roster can look empty one day and full the next.
From booking, a case moves to a first appearance and then to whatever the court decides about release. Everything that follows — plea, trial, sentencing — depends on that first decision.
What to ask when you call
A single call to the jail or the sheriff's office can answer most of what a family needs to know in the first days. Having the questions ready makes the call much shorter.
- Whether the person is currently in custody, and under what booking number.
- When the first appearance is scheduled and which court will hear it.
- What the exact charges are as recorded at booking.
- What the current bail amount is, if one has been set.
- What the facility's visiting rules are and whether visits must be booked ahead.
- Whether the person has any medical or mental-health needs the facility should know about.
Bail in Montana
Bail for arrests in Yellowstone County is set under Montana law. The governing provisions are listed below.
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Mont. Code § 33-17-1602
Surety Bail Bond Insurance License -- Basic Course Of Training -- Temporary License
(1) Except as otherwise provided in this section, an applicant for a surety bail bond insurance license shall satisfactorily complete a basic course of training for bail enforcement agents that is approved by the commissioner.
Montana Code Annotated (official, Montana Legislature) (opens in a new tab) -
Mont. Code § 46-6-508
Arrest By Surety Bail Bond Insurance Producer
(1) A surety bail bond insurance producer who has probable cause to believe that a principal insured by the surety insurer to which the producer is appointed will fail to appear in court, in violation of 46-9-503 (2), or has violated a condition of their release, may use reasonable force to arrest…
Montana Code Annotated (official, Montana Legislature) (opens in a new tab)
Bail in Montana
-
Mont. Code § 33-17-1602
Surety Bail Bond Insurance License -- Basic Course Of Training -- Temporary License
(1) Except as otherwise provided in this section, an applicant for a surety bail bond insurance license shall satisfactorily complete a basic course of training for bail enforcement agents that is approved by the commissioner.
Montana Code Annotated (official, Montana Legislature) (opens in a new tab) -
Mont. Code § 46-6-508
Arrest By Surety Bail Bond Insurance Producer
(1) A surety bail bond insurance producer who has probable cause to believe that a principal insured by the surety insurer to which the producer is appointed will fail to appear in court, in violation of 46-9-503 (2), or has violated a condition of their release, may use reasonable force to arrest…
Montana Code Annotated (official, Montana Legislature) (opens in a new tab)
Source: U.S. Census Bureau · retrieved 2026-09-16
Frequently asked questions
Where are people arrested in Yellowstone County held?
At the county jail, operated by the county. Cities within the county generally do not run their own long-term jails, so bookings are transferred to the county facility.
How do I find someone in Yellowstone County jail?
Contact the Yellowstone County sheriff's office directly. Where no public online roster is published, a phone call is the only reliable route.
What is the county seat of Yellowstone County?
Yellowstone County publishes its county seat, as does the U.S. Census Bureau.
How do I post bail in Yellowstone County?
Bail is set by a judge under Montana law and is normally paid to the court or the county, not to the jail. Confirm the accepted payment method and the exact amount with the court before travelling.
Does Yellowstone County publish mugshots?
Some sheriffs publish booking photographs and some do not. Where a roster is published, the sheriff's own site governs what is shown and for how long. We do not republish individual records.
How long are people held in Yellowstone County jail?
That depends on the case. People awaiting trial are held until bail is posted or the case concludes; people serving a sentence are held for its duration, then transferred or released.
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