The Bodyguard star hired Peggy Detmers to make 17 bronze figures of Native Americans hunting the beasts in the early 1990s for display at a planned five-star hotel.
The resort never came to fruition and the actor's relationship with Detmers turned sour in 2009 when she filed suit for breach of contract, challenging Costner's decision to donate the Lakota Bison Jump collection to his Tatanka museum near the town of Deadwood.
A judge ruled against the artist last summer (11) and allowed the actor to keep the bison pieces at the museum, but Detmers appealed the ruling and took the case to the South Dakota Supreme Court this week (19Mar12).
Costner did not attend Monday's hearing, but his lawyer Kyle Wiese argued that Detmers had shown no signs of discontent when she attended an unveiling ceremony at Tatanka in June, 2003.
He told the court, "All of this conduct - taking part in the dedication ceremony and giving a speech - indicated she was agreeable to put these sculptures at this location for the long term."
However, the artist's legal representative, Andrew Damgaard, insists Detmers only agreed to the museum placement as a temporary solution because she believed the hotel plans were still in the works.
Damgaard said, "It's very clear from the record that people were telling her the resort was intended to be built, that it was intended to be built on that property."
Detmers is seeking to have the sculptures sold, so she can claim half of the proceeds.
A written ruling is expected to be delivered by Supreme Court judges at a later date.