This was a pretty small paperback, sold at Scholastic book fairs in the early 90s. It was meant for late elementary school to early middle school readers. It’s fiction, and I believe it might have been in the format of a diary kept by the main character. Pretty sure the cover had a mountain lion on it.

It was about a boy from Michigan or some other Midwestern state who for some reason had to go to California for a summer (maybe he was in some trouble at school or his parents were getting divorced, don’t remember). I remember a scene with a rattlesnake, where someone ends up chopping its head off with a garden hoe.

The ending involved him getting lost in a canyon and stalked by a mountain lion. He was about to try fighting it with a rock when search and rescue showed up to help him.