History Established in 1933, Duluth Teachers Credit Union was formed by a small group of Duluth, Minnesota school educators to meet the financial needs of the Duluth School District. In 2014 the field of membership was expanded to include anyone living in South Saint Louis, Carlton and Douglas Counties as well as Two Harbors. Today Duluth Teachers Credit Union serves over 8,800 members in the region. Duluth Teachers Credit Union operates three branches in the Duluth area and offers many online services at dtcu.net