Needless to say we concluded our nature hike right there.
In my opinion, raccoons make the scariest sound of all.
“Wife and I were hiking in a state park near Napa Valley and heard the scariest growl come out of the bushes.”
What park was that and when? There have been noisy cats on the west side of the Valley for close to two decades.
A large group of us were on an "owling outing" after dusk down in Southern California when we heard the rustling of something stalking us through the brush. The guide said it was a mountain lion, and we were mostly pretty excited about it until it flanked us and growls started coming from in front of us.
The guide didn't think it would attack; it was making way too much noise and seemed to be telling us, "I was here first, turn around." We decided to do just that, since we had kids with us.
Exciting, but a little scary.