Credit: TMZ

Take a hike, Sandy and Ryan!

Ryan Reynolds joined Sandra Bullock and her adorable son Louis, one-and-a-half, on a trek though Grand Teton National Park in Wyoming over the weekend. In pics posted on TMZ, Reynolds, 34, carried little Louis in a backpack carrier as Bullock, 47, and another pal strolled behind, taking in the gorgeous natural beauty.

Reynolds, Bullock and other friends have been vacationing in nearby Jackson Hole, where Bullock's father owns a home.

While the Proposal costars make a gorgeous pair, the pals are keeping things platonic for the time being. "They're very close and talk together a lot," a Reynolds pal recently told Us. "It would make sense for them to pair up romantically, but for now, they're just friends."

The duo have more than Hollywood careers to bond over, of course: In 2010, both suffered the painful end of their respective marriages (hers to Jesse James, his to Scarlett Johansson).

 "They commiserate over failed relationships," another source says.