This is recommended by one of my small bosses. I had searched through the USA itineraries of the various tour agencies in Singapore and I am quite surprised that no tour agency has included Yellowstone. Naturally, I was a bit puzzled and worried that it may not be as good as I thought. But I will say I am not disappointed.
Day 6 - Yellowstone (Old Faithful)
We had to wake up pretty early (around 3 am?) to catch our flight to Salt Lake City, our transit stop. Before we left Las Vegas, we tasted the Earl of sandwich which is delicious. It's among my top 3 for this entire trip. Salt Lake City is just like Las Vegas. The terrain is the desert kind of terrain. When we reached the West Yellowstone airport, I was rather surprised at the size of the airport. It's real small. It has to be the smallest and most informal airport I have ever seen. In fact, the airplane to West Yellowstone is also the smallest I have ever seen. The air stewardess has to work within a very small area and I am amazed that she can still perform her usual tasks as per normal.
I got to knew much later that West Yellowstone is a pretty small town with a population of less than 1k. Yes, less than 1k! When I thought that the capital of Iceland is sparsely populated, this is even more so. However, the small size of the town makes it easy to navigate around. It's not difficult to find our way around and find our way to the Yellowstone National Park. It's just a 10 mins drive to the West entrance of the National Park.
After picking up our rented car and placing our luggage in the motel rooms, we drove to Running Bear Pancake restaurant for our lunch. It's a tasty lunch! The pancake was soft and the maple syrup was hot and nice. It's also among my top 3 meals during this trip. The waitress who served us was friendly and caring. She made us feel warm and welcome.
After lunch, we drove to the national park. We had to pay an entrance fee of US$25. This last for 7 days and includes Grand Tetons which is too far for us to pay a visit. We had one destination in mind- The Oldfaithful Geyser which is one of the most famous geyser in the national park. When we reached, we were only about half an hour away from the predicted timing of the eruption. Hence, we decided to wait for the eruption. The clouds were low and beautiful that particular afternoon. It's a sunny day and the temperature was in fact warmer than I have expected. It feels like the mid 20s. Our patience paid off when we eventually saw the eruption of the Old Faithful. Its eruption is longer than the one I saw in Iceland and it's of a greater height.

<Old faithful erupting>
We walked around the Old Faithful area. It's a rather huge area and we only managed to cover a small part of this area. We covered part of the Southern section of Old Faithful area. We saw pools and geysers. It's a casual walk and we were in time to have another view of the eruption of the Old Faithful Geyser from far. It's little wonder why the geyser is named as such. Just when we were about to leave the area, we saw another geyser eruption from far. It's a cone type of geyser, but I seriously couldn't figure out which geyser that was.
Day 7- Yellowstone Area (The Lower Geyser basin, The mid and the upper Geyser basin)
We started the next morning pretty late as we wanted to have more hours of sleep. Breakfast is at our motel and it's free! There's french toast, pancakes, cookies, toast and even fruits.Taking into consideration that it's free, it can be deemed to be quite a good meal.
After the breakfast, we set off to the national park. We went to the lower basin first. I was having quite high expectations of the Fountain Paint Pots but it's not of my top fave. Fountain Paint Pots is a bubbling mud pool which is like a clay pool. I visited the miid geyser basin with high expectation of Grand Prismatic Spring. Actually, the usual postcard pic is an aerial view of the spring. The spring is big and hence, it's impossible to have an aerial view. Nevertheless the spring is still nice! I also like the Opal pool.

<"Entrance" to the mid geyser basin>

<Grand Prismatic Spring>

<Opal Pool>

After the mid geyser basin, we also visited the biscuit basin. We took the trail hike to reach the mystic falls.

Mystic Falls is not the most scenic waterfall.

<Mystic falls>
<Jewel geyser in action!>
We drove to the Old Faithful area after the Biscuit basin. We did a quick sandwich lunch at the Old Faithful Lodge and viewed another eruption of Old Faithful before we toured the North Section.
When we visited the North Section, the geysers weren't very active. However, we saw a lot of beautiful pools. The highlight of the day is the Morning Glory Pool. I really like the rich colours of the pool. It's a pity that it has lost its original blue colour due to the clogging of the vents by the rubbish threw by people.

<Castle Geyser>

<Belgian Pool>

<Beauty pool>

<Chromatic pool>

<Morning Glory Pool- My favourite pool!>
The night at West Yellowstone was pretty cold. The temperature dropped to 40 F aka 4 degree C when we went out for dinner.