The majority of cases before the Montana Supreme Court are decided based upon the written briefs submitted by the parties. However, the Court may decide that a case requires further discussion, in addition to what the parties have argued in their written briefs. In such cases, oral arguments are scheduled in open session before the Court. Approximately 15 cases a year are scheduled for oral argument.

Oral arguments are tightly structured and timed. The counsel for each party is allowed limited time to make an argument. The times typically range from 20 to 40 minutes and are set forth by the Court in the order setting oral argument. 

While this format allows the counsel brief opportunity to further develop their arguments, it also gives the Court an opportunity to ask questions of the attorneys on points which the Court needs clarification.

A majority of oral arguments take place in the Montana Supreme Court Courtroom, located at 215 N. Sanders, Helena, Montana. The Court does schedule a few arguments to be heard in different cities around the State. See the list of scheduled oral arguments below.

All oral arguments are open to the public.  

Click here to see list of previous oral arguments 



OP 22-0034

LUSTRE OIL COMPANY, LLC, and EREHWON OIL & GAS, LLC, Plaintiffs and Appellants, v. ANADARKO MINERALS, INC., and A&S MINERAL DEVELOPMENT CO., LLC, Defendants and Appellees. Oral Argument is set for Wednesday, October 26, 2022, at 9:30 a.m. in the Courtroom of the Montana Supreme Court, Joseph P. Mazurek Justice Building, Helena, Montana.

Live-streamed through the Court’s website at

After an oil spill within the Fort Peck Indian Reservation, A&S Mineral Development Co. acquired some oil and gas leases from Anadarko Minerals, Inc., as a part of a settlement agreement. A&S is a company that was formed to develop oil and gas leases on behalf of the Assiniboine and Sioux Tribes of the Fort Peck Reservation. It is a limited liability company, wholly owned by the Tribes, chartered under Delaware law.

Lustre Oil Company claims that it had acquired ownership of these leases prior to the settlement agreement and thus Anadarko could not have assigned them to A&S. Lustre sued to quiet title to those leases. However, the District Court dismissed the suit, concluding that A&S was an indispensable party to the case, but that A&S was an arm of the Tribes and therefore has sovereign immunity.

On appeal, Lustre argues that A&S is not an arm of the Tribes and does not have sovereign immunity. Lustre further argues that the Tribes and A&S waived any potential sovereign immunity claims and that the District Court incorrectly concluded that A&S could not be joined as a party to Lustre’s lawsuit.