Seitz Insurance Agency Share: Insurance Seitz Insurance Agency Visit Website Request Info 114 2nd Ave SE / PO Box 326 Sidney, MT 59270-0326 (406) 433-1411 (877) 884-3680 (406) 433-3603 (fax) LinkedIn Facebook Hours: Monday - Friday from 9:00 am to 5:00 pm. Map What's Nearby? Distance: 5 10 15 20 25 50 mi.