From Jackson, Wyoming head north on Highway 191/89. Just past the boundary of Grand Teton National Park take the first right at the traffic circle onto Gros Ventre Road. Moose can be anywhere along the river which parallels the road.
The stretch of river behind the Gros Ventre Campground is always a good place to find moose. I always stay in the campground for this reason. If not staying in the campground, follow the campground rules for visitors which usually requires you park at the amphitheater parking lot and walk in.
During the fall rutting season, the Gros Ventre River, just north of Jackson, Wyoming and along the southern boundary of Grand Teton National Park, is teaming with moose. As the river nears the park campground and the small isolated community of Kelly, it runs through a forest of willows and cottonwoods which in a good year are full of autumn yellows. As this dominant bull moose walked along the opposite bank of the river from me, another smaller moose emerged along the river's edge in front of me and walked directly between me and the larger moose. The big bull turned and charged toward the smaller intruder, sending him running. Since the smaller moose was in the lower river bed, and the big bull and myself were on higher ground, I was able to shoot over the small moose and capture the charge head on. This image was at the beginning of the series of shots before he lowered his head. I thought showing him at his full height, with the intense look of dominance in his eyes, demonstrated the full magnificence of the animal.