Found a Flight Plan here to visit a good portion of the Yellowstone National Park: https://simulatedaviation.com/flight-plan-yellowstone-national-park-tour/
I did have to manually manipulate the Flight Plan once it was created. For some reason, MSFS rearranged the waypoints and put the U53 and 29S at right after the take off runway. I corrected that manually in the Flight Plan file before loading it. Then I noticed that for some reason the flight plan started at the last leg instead of the first. I corrected that in the G1000 before starting and then I was able to fly the plan. Very strange behavior.
Yellowstone, the Great Divide Basin, Big Horn Mountains, Black Hills, and much of Wyoming are some of the most realistic looking areas in the game, in my opinion. I feel like I’m actually there. Perhaps the designers used Wyoming as a model, or it might be just a coincidence of the simulator’s limited autogen and Wyoming’s vast openness, but the evergreens, prairie grass, and sparse isolated buildings match really well. Even the high visibility sky conditions and weather look great up there. It’s one of the better places to wander around in the smaller aircraft.