My husband and I are spending ONE (1) day in Yellowstone. We will be staying in Debois, WY and driving an hour north to the Southern entrance. We are used to snow/mountains, but not together and are in great shape, . We have both been to Yellowstone and seen the typical old faithful and ETC. What good hiking trails or things to do can we see coming from the south considering Late May. On Sunday, we are doing Grand Tetons for the Day. What gear would be good (snow boots/ regular boots with snow cleets, winter hiking pants/ regular hiking with thermal underwear).