How to Mail a Letter to Someone at Yellowstone County Detention Facility (what to send, where, and what happens next)

Mail at Yellowstone County Detention Facility runs on two separate tracks. Getting this right determines whether your letter reaches the person you're writing to - or goes nowhere. Personal mail isn't accepted directly at the jail. Instead, a third-party vendor scans it and delivers it to the inmate electronically. Legal mail works differently: send it directly to the facility's street address, not the scanning address. This setup exists because of contraband concerns. Think of "personal letters" and "legal mail" as two completely different processes with different addresses and rules. Send personal mail to the jail? It won't follow the right system. Send legal mail through the scanning address? It won't be treated as legal mail.

1. Write the inmate’s name and jacket number - include both so the mail can be matched to the right person.
2. Address the envelope to the scanning P.O. Box (not the jail) - personal letters should be mailed to:
3. Yellowstone Co. Detention Facility
4. P.O. Box 591
5. Long View, Texas 75606
6. Do not mail personal letters to the facility street address - that address is for legal mail, not personal letters.

• ✓ Include a clear return address on the envelope.
• ✓ If you’re unsure you have the correct inmate name/jacket number or you have a mail question, contact the YCSO Civil Division at 406-256-2959 or SOCivil@yellowstonecountymt.gov before you send it.

Because personal mail gets scanned, Yellowstone County Detention Facility has specific limits on what you can send. Keep your letter to five pages or fewer. Anything longer won't be scanned and won't be delivered. Write on the front of each page only - the scanner doesn't capture writing on the back. Stick to standard paper: maximum letter size is 8.5 x 11 inches. You can include a photo, but only one per letter. The scanning process handles personal letters only. It won't accept legal mail, medical mail, books, magazines, or packages.

• ✓ Keep it to 5 pages max (or less).
• ✓ Write on the front of each page only (no double-sided letters).
• ✓ Use paper no larger than 8.5 x 11 inches.
• ✓ Include no more than 1 photo.
• ✓ Don’t send books, magazines, or packages through the personal-mail process.

Once you send personal mail to the scanning address, the original letter and everything inside it gets destroyed. The facility doesn't hold originals, forward them, or return them to you. This matters most for photos and keepsakes. Don't include anything you'd want back - original photos, sentimental cards, or anything irreplaceable. If you send a photo, remember the one-per-letter limit, and plan on not getting it back.

1. Confirm it qualifies as legal mail - legal mail is only mail sent directly from the inmate’s attorney or the court; personal mail marked “legal” won’t be treated as legal mail.
2. Label it clearly - stamp or write “LEGAL MAIL” on the outside, and address it to the inmate’s name.
3. Send it to the facility (not the scanning P.O. Box) - mail legal correspondence directly to:
4. 3165 King Ave E
5. Billings, MT 59101
6. Include verification information - the return address must list the sending entity’s name (attorney, law firm, court, etc.) and include a phone number for verification.

Common Mistakes and Checklist

• ✓ Personal letter addressed to the P.O. Box scanning address (not the facility street address).
• ✓ No more than 5 pages total.
• ✓ Front side of pages only (no writing on the back).
• ✓ No books, magazines, or packages included.
• ✓ Legal mail (attorney/court) sent to 3165 King Ave E, Billings, MT 59101 and marked “LEGAL MAIL.”

Want to avoid delays? Double-check everything before you seal the envelope. For questions about mail or other inmate services, contact the YCSO Civil Division at 406-256-2959 or SOCivil@yellowstonecountymt.gov.

Call first if you're unsure whether something counts as legal mail, if you're sending a large set of documents, or if you don't have the right inmate information (name and jacket number) for the P.O. Box address. The YCSO Civil Division handles inmate service questions: 406-256-2959 or SOCivil@yellowstonecountymt.gov.