It’s about a boy who runs away from home and lives in the woods. I even have a name: The Other Side of the Mountain. Only that’s not getting me the book I’m looking for in Amazon or Wikipedia. I know I didn’t make up this book.
My Side of the Mountain?
Other side of the Mountain is about the skier who gets paralyzed.
My Side of the Mountain is what your looking for.
Thank you!
Enjoy the book. Let us know if you’re tempted to make your own acorn-flour pancakes, and how they turn out. 
The part I really remember (I read this when I was maybe 9 years old. That was a long, loooong time ago) was how he boiled water in a leaf. I do not know why this stuck with me.
ETA: I also remember being crushed when I found out it was fiction.
I remember the part where he ripped open a squirrel to eat its liver.
Or something like that.
Rabbit. He was cooking a rabbit and realized he craved the liver and cooked it up. Later he read that liver is high in vit C and it was winter, so he was probably deficient.
Ask me another. I know this book. 
I remember the ending being quite anti-climactic. IIRC his family shows up and goes to stay there with him, with everyone living happily ever after After everything he goes through and the things he survives it all just…stops. It wasn’t even like he needed rescuing or anything.
Oddly, I never even finished this book, and I remember that part too. I feel strongly the leaf used was skunk cabbage.
There are two sequels: On the Far Side of the Mountain and Frightful’s Mountain.
Neither is anywhere near as engaging as the first.
Hatchet by Gary Paulsen is also a good book in this genre, as is Tunnel in the Sky.
This was one of my favorite books when I was a kid. One of the things that fascinated me was that he hollowed out a tree trunk to use as a shelter. (Presumably the trunk was at least five feet in diameter.) He even built a little clay stove in the shelter to use for heat and cooking.
I loved this book as a kid, and thought that it would help me to survive once I ran away to the wilderness. I memorized the various facts in the book.
I re-read it a few months ago, for the first time since becoming an adult. I didn’t find it nearly as good. With some juveniles, when you go back and read them as an adult, you find more layers and more to the story. With this one…well, it was a nice escapist story, but I didn’t find anything deeper in it.
That could be why I didnt find the two sequels as engaging.
I have re-read the book many times into my adulthood and loved it each time, but also didn’t find the sequels great either. I think they just didn’t have te heart that the first book had.