For the past 80 years A.G. O’Brien has led the Northland in providing the highest quality services in Plumbing, HVAC, and Fire Protection. We pride ourselves in doing work that is second to none, and our portfolio includes projects for the area’s biggest businesses and community leaders, including: UMD, Cirrus, KwikTrip, St. Scholastica, Essentia Health, Clyde iron works, Fond Du Lac Band, Lake superior college, Members Co-op credit union, Holy rosary church and campus.