Jefferson County Jail
Jefferson County Jail
County Jail / Adult Detention FacilityMailing Address
[Inmate Full Name] — [ID if known]
Jefferson County Jail
P.O. Box 588, Boulder, MT 59632
Jefferson County Jail
P.O. Box 588, Boulder, MT 59632
Physical Address
P.O. Box 588, Boulder, MT 59632
Governing Agency
Jefferson County Sheriff's Office
Inmate ID
Inmate / Booking ID — Not required
Last Verified
September 27, 2026
Facility Mailing and Service Information
Use the incarcerated person's full legal name and a complete sender return address. Verify the current Jefferson County Jail mail rules before sending correspondence.
Last verified: September 27, 2026
Verify the facility's current photo size, quantity and content restrictions before mailing photographs.
Last verified: September 27, 2026
Verify the facility's current book, publication and package rules before sending books or magazines.
Last verified: September 27, 2026
Do not mail cash unless the facility explicitly permits it. Use the current approved inmate-account deposit method.
Last verified: September 27, 2026
Verify current visitor approval, identification and scheduling requirements before travel.
Last verified: September 27, 2026
How to Address Your Letter
Use the incarcerated person's full legal name and a complete sender return address. Verify the current Jefferson County Jail mail rules before sending correspondence.
About Jefferson County Jail
Jefferson County Jail is a Montana county detention or jail facility record reviewed for current status and mail routing on 2026-09-27.