On day 102 of “The Ultimate USA Road Trip” we drive from Old Faithful in Wyoming over the Grand Loop through Yellowstone National Park to Gardiner in Montana. The route is short but you do need a lot of time to drive it because most attractions with beautiful active geysers and beautiful lakes with sometimes breathtaking colors are located along this part of the Grand Loop. The route follows the course of the Firehole river, which contains several waterfalls.

Before we start the ride, we fill up with gas and do some shopping for today's ride. The Grand Loop Road in Yellowstone Park is the best way to reach the most beautiful sights in Yellowstone National Park. This stretch of Grand Loop Road runs from the Old Faithful area to Madison Junction and is the most popular and has the most geyser basins. Keep in mind that traffic and attractions can be very busy, so get an early start and make sure you plan enough time to enjoy all the beauty of this part of the park.

The most popular spots are marked with a POI and Waypoint, but there is much more to see and for the hiking enthusiast there are several hiking trails that lead you to remote geysers and springs.

The first stop is near Old Faithful at Black Sand Basin, one of a group of geothermal hot springs and geysers. The spring is too hot to use as a mineral bath, as the scorching water of 93 °C (200 °F) or hotter water has proven fatal.

The second stop just 10 minutes away at Biscuit Basin is more interesting, especially early in the morning on a sunny day. It is perfect to see the beautiful colors of the pools and there will be fewer people so you can enjoy them to the fullest.

There is a boardwalk you can follow to view the pools, springs and geysers. There are not many geysers in the Biscuit Basin, most are small bubbling springs. The main geyser visible from the designated boardwalk is the Jewel Geyser, which spouts approximately every ten minutes.

The main attractions are the Black Opal, Black Diamond and Sapphire Pools, they are breathtaking (not just because of the smell) with beautiful and vibrant colours.

It may be interesting for hikers to plan a stop at the Fairy Falls. The Fairy Falls Trail is a 2.6 mile hike to the falls. You will also pass the Grand Prismatic Spring Overlook with great spring views. It takes about 2.5 hours to walk the route. There are also two small swimming pools with beautiful colors in the parking lot.

We stop at the Grand Prismatic Spring in the Midway Geyser Basin, it is the largest hot spring in the United States and the third largest in the world. Grand Prismatic Spring was noted by geologists working in the Hayden Geological Survey of 1871 and named by them for its striking color. The colors correspond to most of the colors visible in the rainbow propagation of white light through an optical prism: red, orange, yellow, green and blue. This is a breathtakingly beautiful place to visit.

We leave the Grand Loop for a short drive on Firehole Lake Drive (when open), a short 3.1-mile one-way road with geysers and hot springs visible from the road. You can also stop and take a walk on the boardwalk.

Hikers can visit the Fountain Paint Pot area. You can walk the trail and see several hydrothermal features that are expressions of Yellowstone's still active volcano. Within this geological system, every type of thermal feature is represented. They can be grouped into two general categories: those with a lot of water (hot springs and geysers) and those with little water (mud pots and fumaroles). Despite their structural similarities, no two features are exactly the same. The walk takes about 30-45 minutes.

We visit a number of waterfalls along the route, the first is the Firehole Falls, a short walk from the car park you will see a beautiful 12 meter high waterfall in the Firehole Canyon. Another beautiful and larger waterfall to see is the one in the Gibbon River with a drop of about 26 meters.

We stop to see the Artists Paint Pots, a group of more than 50 springs, geysers, vents and, most importantly, mud pots. These exhibit varying shades of blue, gray and brown and have a range of different textures, with behavior changing throughout the year depending on the amount of underground water. All active features can be seen via an easy 0.9km trail through partly wooded country that is largely flat apart from a short climb and descent over the hill overlooking the basin.

We visit the Norris Geyser Basin and Museum; this basin contains many geysers. The geysers are of different sizes and have different eruption properties. The most famous geyser in this basin is the Steamboat Geyser, which produces the highest eruptions of all the geysers in the park and can spout to a height of over 90 meters. The Norris Geyser Basin is the hottest in the park.

You can visit the National Park Ranger Museum, housed in a log cabin across the road, staffed by very friendly and helpful Rangers. The museum tells the story of the Park Rangers and is very interesting and informative.

We stop to take some pictures of the Roaring Mountain and Sheepeater Cliffs. Roaring Mountain (2,485 m) in Yellowstone National Park is named for the numerous fumaroles on the western slope of the summit, which in the early 20th century were loud enough to be heard for miles. The Sheepeater Cliffs are a series of exposed cliffs composed of columnar basalt in Yellowstone National Park. The lava was deposited about 500,000 years ago during one of the periodic basalt floods in the Yellowstone Caldera, and later exposed by the Gardner River. The cliffs are seen as a textbook example of a basalt flow with well-defined joints and hexagonal columns. They are named after a group of Eastern Shoshone known as Tukuaduka (sheep eaters).

We drive through the Golden Gate Canyon. Glen Creek flows north through the gorge on its way to the Gardner River, descending from 8,000 feet at Kingman Pass to just under 6,000 feet in less than 3 miles, so this is an intense downhill ride. The gorge's name Golden Gate is derived from the yellow hue of the area's rocks, which shine like gold in the sun. This road was first built through the Golden Gate in 1884-1885, replacing a steep, difficult road over Snow Pass. The work included a wooden trestle where a rock wall made leveling impossible. In 1900 the viaduct was rebuilt as a concrete structure, the Chittenden Viaduct being replaced in 1930-1934. The drive through this gorge is amazing and the views are breathtaking.

The next part of the ride is a tour of Mammoth Hot Springs, which is a large complex of hot springs on a travertine hill in Yellowstone National Park, adjacent to Fort Yellowstone and the Mammoth Hot Springs Historic District. It formed over thousands of years when hot water from the spring cooled and deposited calcium carbonate (more than two tons of Mammoth flow in solution every day). Due to the enormous amount of geothermal vents, travertine, a type of lime deposit, is formed in different colors ranging from brown, orange, red and green colored.

Arriving in Mammoth we stop for a (late) lunch and you can visit the Mammoth Hot Springs Historic District, which includes Fort Yellowstone, where 35 structures still stand from the 1890s and early 20th century, when the American army managed the park .

We leave Wyoming and enter Montana, after a short drive we arrive at the final destination in Gardiner. This town on the Yellowstone River was officially founded in 1880. The area has served as the main entrance to Yellowstone National Park since its founding in 1872. Yellowstone National Park Heritage and Research Center is located in Gardiner and houses National Park Service archives, Yellowstone museum collections, and reference libraries. Enjoy your stay. There are several hotels, B&Bs and lodges on both sides of the Yellowstone River.