Kevin Costner often wonders how he can "make a difference" in life

Speaking on 'The Will Cain Show', he said: "While we all enjoy [the Yellowstone national parks], very rarely do we actually understand how they came to be.

"And when you think about things in life, it's like, are we ever going to make a difference in our life?

"I mean, I ask myself that. Everybody does. I mean, there's a billion of us on this planet now. What do we do? But it's a story about how men and women can really make a difference through a force of will."'

The Hollywood actor doesn't want to "pound people in the head" with the new documentary series but just wants to "educate" others on American history.

He said: "Not to pound people in the head, but just to educate. But again, you know, America found a way where land would have a use other than just exploiting it, that the natural beauty could perhaps be turned into a level of commerce where people would come and what they saw as a child, their own children would see."

The Academy Award-winning star was then asked what draws him to scripts he takes on, and he admitted that he tends to go for the ones that steer away from the ovious " notion of heroism" often seen in movies.

He added: "The notion of heroism when no-one's looking. I think when you're a child or young man or young woman and you see that, you realize, you know, the heroism of a woman who works three jobs, you see her four in the morning, every morning at a bus stop. And by the end of the evening, when she gets home so tired and makes a meal for her kids, she's gone to three different places to work in movies. We can sometimes depict that and we lay music to it, and suddenly we know who's important. Suddenly we know who is powerful, who is a hero, a hero in her own family, that she would work that way to make life better for her children."