Juniata County Offices--jail Bridge St Mifflintown, PA 17059 Phone : (717) 436-8448 Business Category Government Offices-County Government Offices & Public Schools Juniata County Prison Bridge St & 3rd St Mifflintown, PA 17059 Phone : (717) 436-8448 Business Category Correctional Institutions Juniata County Offices--juniata County Prison Mifflintown, PA 17059 Phone : (717) 436-8448 Business Category Government Offices-County Government Offices & Public Schools