Where I live we have an active black bear and mountain lion population. Although I have never seen a mountain lion, I have had several bear encounters which really weren’t that scary.
Awhile back, I attended a symposium on mountain lions( after an attack in nearby Orange county where a man was killed and two women were injured). The mountain lion expert said that the mountain lion is more closely related to the cheetah than the African lion and is the second fastest animal behind the cheetah. He went on to tell what to do if you encounter a lion. A couple of things he brought were, that if you go into lion country, it would not be a bad idea to put patches or stickers of eyes on the back of your hat or helmet, since lions suprise attack from behind in almost all cases. He also stated that bells or whistles actually attract mountain lions, or any cat for that matter because cats are curious by nature.
I have never seen a mountain lion, but have seen fresh footprints and also spotted a dead, halfway eaten deer in a tree and a dead dog in a shallow grave.