They’re all here. Of course you are more likely to be seriously injured by a deer running into the road than a predator. Deer are not smart about cars or bikes–rather like big squirrels. But they are really smart about food and water, so they like to hang around where there are sprinklers and green vegetation in the summer. There are far more deer in my yard than out in the forest. Deer get even stupider in the late fall when the bucks come down to town.
Mountain lions are also smart about food, but they are much smarter about people, so you are most likely to come across a mountain lion on the outer fringes of rural areas. Use common sense especially at dawn and dusk. I’ve come across bears in the forest, and they always run away (so far). Clunky noisy bikes, good smart bears. Use bear-safe food storage in the high country. There are also dogs. They behave exactly like dogs.
Deer flies are small flies that form clouds around your eyes. They seem most prevalent around 3,000-5,000 feet along exposed ridges in mid-summer to fall. They don’t hide in the shade like gnats or midges. They don’t seem to bite, but are very annoying. They like the pace of a bicyclist struggling up a steep hill. They aren’t everywhere–I’ve gone months without encountering them, but when they find you, you will probably wish you had a headnet. I throw a headnet in my bag for the summer just in case. You will only need it when climbing; when descending they can’t keep up, and if you’re like me, you’ll prefer to be able to see where you are going. Don’t spit when wearing a headnet unless you are strangely attracted to that sort of thing.