From Idaho Falls take HWY 20 north. The exit will be on your left and if you reach Island Park you've gone too far.
Harriman Stae Park is located about 80 miles north of Idaho Falls. It's an ideal winter location for photography. As you walk, cross-country ski or snowshoe around this landscape you may encounter moose, geese, swans, deer, elk and ducks and that's a short list.