After driving down US 191 through the Gallatin Canyon from Bozeman, enter Yellowstone National Park via West Yellowstone. Take the lower loop, starting at the Madison Junction. Look for Trumpeter Swans on the rivers and bison on the roads. Stop to walk the boardwalks of all the geothermal features, including Grand Prismatic Spring. Continue on to see the ever-punctual Old Faithful and stop for a night at the Old Faithful Lodge. The next day, drive to Yellowstone Lake and spend a day on the water. Finish your lower loop journey by driving through the Norris Geyser Basin for more geothermal wonders.