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How to send a letter to an inmate at Yellowstone County Detention Facility

To write to someone held at Yellowstone County Detention Facility, address the envelope to the inmate's full name and ID number, Yellowstone County Detention Facility (Attn: Mail Officer), 3165 King Avenue East, Billings, MT 59101. Yellowstone County Detention Facility is the jail for Yellowstone County, Montana, run by the Yellowstone County Sheriff's Office. Mail is opened and inspected — include your full return address, and double-check the person is still in custody, since people are released or moved from a county jail quickly.

Inmate mail — Yellowstone County Detention Facility

[Inmate's full name]  [ID number]
Yellowstone County Detention Facility (Attn: Mail Officer)
3165 King Avenue East
Billings, MT  59101

Put the inmate's full name and ID number on the first line, and your full return address in the corner — mail without either is usually rejected.

Verified August 2026yellowstonecountymt.gov

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Your name
Your return address

Yellowstone County Detention Facility (Attn: Mail Officer)3165 King Avenue EastBillings, MT 59101

Your letter, printed and mailed for you.

Key facts

  • Send mail to Yellowstone County Detention Facility (Attn: Mail Officer), 3165 King Avenue East, Billings, MT 59101 — the jail's own mailroom.
  • Write the inmate's full name and ID number on the envelope, plus your full return address, or the letter is returned.
  • All incoming mail is opened and inspected for contraband before it reaches the inmate.
  • Do not enclose cash, checks, gift cards, or anything other than paper — prohibited items get the whole letter rejected.
  • You MUST include "Attention Mail Officer" in the address — mail without it is returned to sender.
  • Photos are accepted if free of inappropriate content; no packages.
  • Newspapers and publications must come directly from the publisher.
  • County jails move fast — people are released, bailed out, or transferred within days. Confirm the person is still in custody before mailing anything time-sensitive.
  • PostPal prints and mails your letter for you the next business day for $5 — with your return address printed so they can write back, and no printer, envelope, or stamp needed.

How to send your letter

  1. 1

    Confirm the person is still at the jail

    County-jail populations turn over quickly. Check the Yellowstone County Sheriff's Office's online inmate roster to confirm they're still at Yellowstone County Detention Facility — and get their ID number — before you mail anything.

  2. 2

    Address it correctly

    First line: the inmate's full name and ID number. Then Yellowstone County Detention Facility (Attn: Mail Officer), 3165 King Avenue East, Billings, MT 59101. Add your full return address in the top-left corner.

  3. 3

    Keep the contents allowed

    A plain letter on white paper is always safest. You MUST include "Attention Mail Officer" in the address — mail without it is returned to sender. No cash, gift cards, or any object other than paper.

  4. 4

    Send it without a printer

    Write or upload your letter in PostPal with this address prefilled, and we print, envelope, and mail it via USPS the next business day for $5 — your return address printed so they can reply.

Common questions

How do I address a letter to an inmate at Yellowstone County Detention Facility?

Put the inmate's full name and ID number on the first line, then Yellowstone County Detention Facility (Attn: Mail Officer), 3165 King Avenue East, Billings, MT 59101. Include your full return address in the top-left corner of the envelope.

Is mail to Yellowstone County Detention Facility opened or read?

Yes. All incoming mail is opened and inspected for contraband before delivery, and non-legal mail can be read.

What if they've been released or moved?

It happens fast at a county jail — people bond out or transfer within days, and the letter won't be forwarded. Check the Yellowstone County Sheriff's Office's inmate roster to confirm they're still at Yellowstone County Detention Facility before you send.

What can I send to Yellowstone County Detention Facility?

You MUST include "Attention Mail Officer" in the address — mail without it is returned to sender. Photos are accepted if free of inappropriate content; no packages. Newspapers and publications must come directly from the publisher. When in doubt, a plain letter on white paper is always accepted.

Can the inmate write back to me?

Yes, if you include a complete return address. PostPal prints your return address on the letter for you.

Sources

Addresses verified August 2026 against official sources. Always confirm on the official site before time-sensitive filings.

See the full US county & city jails rules — what you can and can’t send, photos & more →

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