What was this kidnapping movie called?

I remember watching a movie about a family who go to the woods for a
*vacation. The son and the wife are kidnapped, and the man tracks
them down. eventually he writes either sign-language or something
else that his son knows on a rock-face on a river.
I've tried google, bing, and yahoo, and like always they give me back
a bunch of crap.

Please help me out, because I would greatly appreciate it.