Robert Redford took A Walk in the Woods to his own Sundance Film Festival.

The 78-year-old actor, director and producer had long hoped to adapt Bill Bryson's 1998 travel book about two friends hiking the Appalachian Trail. It finally came together last year, and director Ken Kwapis submitted it to the festival director without Redford's knowledge.

And that's how Redford ended up making the rounds to media outlets at the festival that he helped launch more than 30 years ago.

"The circumstances, maybe you can call them weird, but I just call them serendipitous. It's just one of those things that came together. It does feel strange with Bill Bryson sitting next to me. That's a little strange," Redford says. "We were sitting in the screening last night. I found myself nervous that he was sitting next to me and I was playing him."

Redford said he'd originally hoped to re-team with Paul Newman to make A Walk in the Woods. But after Newman died in 2008, the project floundered.

"I read the book many, many years ago and I found myself laughing out loud and I don't do that. And that made me pay attention to the book on the whole, and I thought this is a project I think I can be in as an actor, as a character," Redford says. "And initially I thought of Paul Newman because that was way back. I thought that it would be a wonderful third part for Paul and I to do, because it had similar personalities the other two had."

"Then it became a matter of perseverance, passion and obstinacy. I wasn't going to give it up because it was not coming together the way I had hoped. And then finally it has come together and here we are."

Nick Nolte eventually was cast to fill the part of Katz, the friend that accompanies Bryson on his walk. The two actors shifted the focus of the film from rediscovering America to also pondering their own mortality.

"I was thinking about a journey that was being taken by two people who were once friends who fell out and were going to come back together again through some kind of desperation. Last chance cafe or last chance before it's too late or before you're going to die - all that I thought was pretty powerful emotional stuff as a motive," Redford says.

Nolte, 73, says the two take slightly different approaches personally to aging - but he was glad to make a friend through the film.

"This I like because I've only got death left, you know. And that's all Bob has. Of course, he denies that but you know - that's the big event. I do have a 7-year-old daughter so that's been a blessing. It sparks you alive. It really does," Nolte says.

"Bob has been a good addition as far as friends in my life - not only as an actor but as a friend."

The Sundance Film Festival continues through next weekend.