Kevin Costner gives exclusive look behind new Fox Nation series

Legendary actor Kevin Costner is teaming up with Fox Nation to bring you Yellowstone to Yosemite.

Costner retraces the steps of Mountaineer John Muir and President Teddy Roosevelt , who took a three day trip through Yosemite in 19 O3.

The expedition LED Roosevelt to sign legislation that began essentially the National Park System .

John Muir and Teddy Roosevelt worked together to save Yosemite .

The two men were in some tough situations, as you know, taking horses through 14 feet drifts.

They knew that what they were trying to do was important, but they just felt it in their bones.

"I'm curious, what are you going to do next? If we do this again at Fox Nation , which park are going to next?.

Kevin Costner: How's the community after the fires there to fix reflected reflected not just the Palisades , but you know, out there in the valley.

He says he took in four families who weren't sure they were ever going to see their homes again.

Costner says he's familiar with John Muir and Yosemite , but there's also a moment where we have to say enough.