Congrats on the Gyrfalcon visit, that is really special!
The most memorable Peregrine sighting I ever had was at the canyon of the Little Colorado River, where it is very deep and narrow. I saw 2 peregrines flying over the canyon and suddenly one of them dove straight down into the canyon. I followed his dive in my binocs and watched him pull out just above the water, then slowly circle up and up until he rejoined the other bird far above the canyon. The sight of the blue-grey bird circling against the red canyon walls is something I will never forget!