Willow Flats is one of the best areas to spot moose at Grand Teton National Park in Wyoming. I got lucky with the weather on this particular morning and was gifted with a great combo of fall colors, classic blue sky and clouds hanging down low on the mountains. It was even more beautiful in person.
I can't recommend visiting the Tetons in fall enough! Just be sure to check with what's going to be open at the Park at the time you decide to come as they start closing some things in fairly early fall.