Local: 701-444-2211 Toll Free: 888-783-8447
Providing quality legal expertise with common sense and small-town service.

About the Firm

The firm’s home office is in Watford City, located in western North Dakota and nestled in the plains just north of Theodore Roosevelt’s Badlands, south of Lewis and Clark’s Missouri River, and east of the early mountain men’s Yellowstone River. Watford City is the county seat of McKenzie County, which is known as the Island Empire because it is largely enclosed by rivers. McKenzie County’s natural resources have long made it ideal for grazing cattle, cultivating wheat, extracting oil and gas, and enjoying the outdoors and abundance of wildlife. The county’s history is rich in colorful characters, including cowboys of the Old West. The unprecedented oil boom of the Bakken and Three Forks formations have transformed the area from a sleepy western town to a center of oil exploration and development.

explosionJohnson & Sundeen, Ltd. had its origins in 1980 when Dennis Johnson returned to the home of his grandparents and parents to McKenzie County to open his law practice. Lured by the beauty of the West, and a thirst for the rugged Badlands, Ross Sundeen joined the firm in 1993. In 2011, Ariston Johnson left his practice in Bismarck, North Dakota to accept the firm’s invitation to move west. Aaron Weber is a McKenzie County native as well, growing up on a hobby farm south of Alexander.

With determination to give you quality legal service, Dennis, Ross, Ariston, and Aaron offer quality legal skills combined with common sense and small-town service. The firm’s motto is “Small-town lawyer doesn’t mean small-town practice.”

The law firm has extensive experience in complex litigation, including serious personal injury and wrongful death cases. As the lawyers here live and work every day with the oil industry, the firm has a vast resource of professional and industry resources in every phase of oil and gas development, from title issues to drilling, completing, and producing oil and gas wells. This unique access to knowledge and resources enables Johnson & Sundeen accurately to evaluate and analyze the issues that arise not only when things go right, such as negotiating an oil and gas lease, but also when things go wrong, such as when a well explodes or mineral ownership is disputed.

One of the growing legal issues in the oil industry is title curative, where oil companies refuse to pay mineral or royalty owners pending “fixing” some obscure title concern or a probate or heirship issue.   The lawyers of Johnson & Sundeen have a wide breadth of experience in this area. Minerals are real property and treated much like land would be. Johnson & Sundeen have years of experience in examining title to and conveying interests in oil and gas and other real property interests. Probate and heirship proceedings or quiet title actions are often necessary to transfer record title ownership or remove title clouds in minerals. Johnson & Sundeen’s lawyers and legal assistants have extensive experience in helping land owners and their families resolve these matters.


Mineral and oil and gas leases have unique characteristics that are not common in other commercial or land leases. The experienced lawyers of Johnson & Sundeen can help you make the right decisions when it comes to questions of leasing or how an oil and gas lease is interpreted by the courts.


Litigation is also common in the oil and gas industry, including title disputes, lease disputes,surface disputes well, pipeline and construction liens. Johnson & Sundeen is unique in having not only the legal expertise but also a long history of living and working in the heart of the Williston Basin. Our lawyers have direct personal and professional experience that gives them a perspective of understanding not just the law but, more importantly, how it affects their clients on an individual level.

The firm’s case record includes many highlights. For example, in 1991, Dennis successfully completed a multi-million dollar oil and gas lawsuit against the Federal Government that resulted in a continuous stream of income to McKenzie, Billings, and Golden Valley Counties. Several other landmark cases in oil and gas have been successfully litigated by the lawyers of Johnson & Sundeen. The firm has a strong record of success in catastrophic injury cases and title litigation. Our broad experience, long years in oil and gas law, and lifetimes of living in western North Dakota give us the tools to resolve all types of legal issues and the discretion to know which tools are appropriate for any given issue.


The lawyers here do not back down from confrontation. When it is right for our clients, we go to court for them. When necessary, we handle appeals.  Our lawyers have argued before the North Dakota Supreme Court. Both Dennis and Ariston have argued cases before the Eighth Circuit Court of Appeals. Our approach is to handle our clients’ needs from start to finish, no matter how far away the finish line is.

All of our lawyers have true North Dakota roots and understand how people want-and deserve-to be treated. Dennis grew up on a cattle ranch in western North Dakota. Ross grew up on a grain farm in eastern North Dakota. Ariston grew up on a ranch in western North Dakota. Aaron grew up on a hobby farm in McKenzie County and his family has roots in the oil industry and business in western North Dakota.  None of them are strangers to, or afraid of, hard work or long hours. Our lawyers’ agricultural background gives them the farming and ranching work ethic: You don’t quit until the job is done.

That work ethic has led to numerous professional and personal accomplishments. Dennis is the past President and current Board member of the North Dakota Association for Justice, past State Delegate to the American Association of Justice, a current member of the State Bar Association and was awarded the Light of Justice Award in 2016 (the 11th time the award has been given since 1972) recognizing him for his commitment to the civil justice system.. Ross is a member of the National Eagle Scout Association, a past member of the young lawyers executive committee for the North Dakota State Bar Association, a current member of the North Dakota State Bar Association disciplinary committee, a past member of the State Bar Association’s Inquiry Committee West, and Vice-President of the North Dakota Association of Justice. Ariston is a board member of the North Dakota Association for Justice, a member of the American Association of Justice, and a board member of Community Service of North Dakota Northwest Region.  Aaron brings with him his knowledge of what is happening in western North Dakota but also his accomplishments as a certified flight instructor and commercial pilot together with an outstanding academic record both in college and law school.

The firm’s dueling pistols logo represents the firm’s commitment to zealously and ethically advocate for their clients.  Dennis, Ross, Ariston, and Aaron have gained the reputation of tough but fair lawyers who put their respective clients’ interests first.

At Johnson & Sundeen, Ltd., we provide high-quality legal service and advice.

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Partner: Ross Sundeen

In addition to practicing law with Johnson & Sundeen, Ross is the Assistant Dunn County States Attorney.

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Partner: Ariston Johnson

Ariston joined JSLO in 2011 and has an excellent track record arguing appellate cases before the North Dakota Supreme Court.

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Partner: Aaron Weber

Aaron also worked as a wildland firefighter for four summers while in college. He received various certifications and was on one of the largest fires in New Mexico state history, the Las Conchas Fire.

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