Owls have nested at this place for as long as I can remember, although they typically shift nest trees from year to year. By now, this owlet is out of the nest and free-flying. This isn't the first Great Horned Owl owlet spawned in this massive oak, and I suspect it'll play nursery for many more to come.
NOTE ON PHOTOS: The nest cavity can be seen from some distance away (if one knows where to look). In the morning, the sun is to one's back creating excellent lighting. I made these images with either a Canon 5D Mark III or crop-sensor 7D Mark II with a 500 mm fitted with a 1.4x teleconverter. Such camera rigs allow one to keep far away, and still get "keepers" without bothering the birds. Nesting owls should never be approached closely. I'm reluctant to mention the exact site, as all too often publicized owl nests can attract scads of people and such activity can lead to nest failure.