Actor Kevin Costner says he's making his debut as a director because he wants to make sure a frontier film being shot in South Dakota this summer is done correctly.

"I take it very personally what this movie should be," Costner said Wednesday.Costner also will play the leading role in "Dancing With Wolves," which tells the story of Lt. John Dunbar, who is assigned to a frontier post in the 1860s. Dunbar and an Indian man go through changes while learning to understand people of an unfamiliar culture.

"This is not so much a movie of how the West was won. It's more about how it was lost," Costner said.