The firm has represented a diverse clientele, including individuals, corporations, and partnerships, including Fortune 500 companies; medical clinics and surgical centers; insurance and bonding companies; members of the banking and construction industries; professionals such as doctors, architects, engineers, and lawyers; Indian Tribes; and major employers and their employees throughout the State of South Dakota, North Dakota, and Wyoming.

Five of its attorneys have over 50 years of legal experience each.

Costello Porter is proud of its attorneys and their broad range of trial experience in state, federal, administrative and tribal courts. Many of the firm’s attorneys have served as judicial clerks for the South Dakota Supreme Court, the State’s Circuit Courts, and the State’s Federal Courts.

Our members are active in the South Dakota and American Bar Associations, as well as regional and tribal bar associations; the South Dakota Trial Lawyers Association; the Defense Research Institute; the prestigious American Board of Trial Advocates, American College of Trial Lawyers and International Association of Defense Counsel. Attorneys are listed in the Best Lawyers of America and Chambers USA (America’s Leading Business Lawyers).