James E. McMahon

James E. McMahon is Of Counsel at Redstone Law Firm LLP in Sioux Falls, where his practice includes civil litigation, defense litigation, and government relations lawsuits and disputes. He represents individuals and businesses in contested matters and brings extensive public-sector and courtroom experience to complex disputes. His work is informed by decades in practice and by prior service as United States Attorney for the District of South Dakota from 2002 through 2005.

James earned a B.S. from Morningside College in 1973 and a J.D. from the University of South Dakota in 1977. He was admitted to the South Dakota bar in 1978 and later to the U.S. District Court for the District of South Dakota and the U.S. Court of Appeals for the Eighth Circuit. This education and federal experience support a practice involving litigation, governmental issues, and complex legal analysis.

James has a background that includes representing clients in civil and defense litigation while also addressing matters involving government relations. His prior federal service provides direct familiarity with government decision-making, investigations, enforcement priorities, and federal court practice. He has also maintained longstanding involvement with the South Dakota legal community, giving clients the benefit of experience across both private practice and public service settings when disputes involve significant institutional or regulatory considerations.

James E. McMahon has received an AV Preeminent peer rating and is affiliated with professional organizations including the American College of Trial Lawyers and the American Board of Trial Advocates. His practice combines trial experience, federal service, and knowledge of government processes. He helps clients assess complex disputes, prepare for litigation, and navigate legal matters where courtroom strategy and understanding of public institutions are both important.

Law Office Affiliations

• Of Counsel, Redstone Law Firm LLP
• Member, State Bar of South Dakota
• South Dakota President, American Board of Trial Advocates (ABOTA) (2001-2002)
• Member, South Dakota Trial Lawyers Association
• Member, American College of Trial Lawyers
• Member, Second Judicial Circuit Bar Association
• Past Board Member, Ronald McDonald House, Sioux Falls, SD
• Past Board Member, Avera McKennan Hospital
• Past Commissioner, South Dakota Game, Fish & Parks
• Past Board Member, South Dakota Humanities Council

Licensed State

• South Dakota

Education

• University of South Dakota
  Law degree
• Morningside College
  B.S. degree

Awards & Badges