Brockton City Of--city Office Brockton, MT 59213 Phone : (406) 786-3231 Business Category Government Offices-City Village & Twp Government Offices State & Local Government Offices & Public Schools Brockton City Office 716 B Ave Brockton, MT 59213 Phone : (406) 786-3231 Business Category Government Offices-City Village & Twp Legislative Bodies