They are everywhere. I live in Dublin, CA a city of 45K which is just over the hills from the SF Bay. We have mountain lions sighted at least once a year in town. One was hit by a car two miles from my house.
The town south of here, Pleasanton had a city of 65K, had one right in the downtown area at 10 AM on a weekday morning. It had to be shot because it wasn’t heading back to the hills.
In Livermore, A the home of the Lawrence Livermore lab, the moonbats every Good Friday do a sit in at the main gate and get arrested. One year, a cop was putting out cones to block off the street. he looks up and sees a mountain lion 10 feet away! It ran and laid being the sign to the lab and stayed there while the moonbats did their thing(they didn’t seem to care that a cougar was watching them). After it was over, the cops shot it because they couldn’t get a good shot with a tranquilizer gun. They found out it had been hit by a car.
Even in San Jose, the 10th most populous city in the country, There have been two cougars in the last year or so.