The most impressive attractions at the park are the geysers. When superheated water is limited to a confined space, the resulting pressure causes water to erupt to the surface, forming a geyser. This one is called Spouting Geyser...which is exactly what it is doing.

April 18...my last road trip day! On my way home through Washington, I stopped to admire the viewpoint over Dry Falls. A remnant of the last Ice Age, these falls were the largest on earth! At 3.5 miles and 400 feet tall, they dwarf Niagara Falls at one mile wide and a 165 foot drop!

Yellowstone Park is full of natural wonders...geysers, pools, vents, springs. The sights and sounds are just amazing! I was just blown away by this one...Blue Star Spring. Algae living in its waters create the beautiful blue coloration.

Old Faithful might be the most famous...and predictable...geyser in the park, but there are other impressive ones. I was lucky enough to witness the eruption of the Lion Geyser in the Lion Group, since it tends to blow whenever it wants to.

Some geysers have so much water flow and constant pressure that they erupt frequently and violently. I was impressed with the Spasm Geyser. I got some great pics of this one!

My last big park day was April 16...Yellowstone! I was in my early teens when our family visited back in the 70s. Sightseeing was limited because of my little sister, but I do remember some things. As I entered the park, a lot of people pulled over to look at the elk...myself included!

My fondest memories of my childhood visit to Yellowstone was Old Faithful and what you see right here...Fountain Paint Pots! The paint pots are hot springs with a limited water supply, creating mud pots. More water makes the mud soupy, less water thickens it.

With the different temperature variations and conditions, Yellowstone is home to many types of algal growth. Some appear as just colors in springs and pools. Others like this can take on shapes...it looks like strands of black hair!

Geyser eruptions can be quite violent, but the pressure for the most part is constant and controlled. In the Norris Geyser basin is Pork Chop Geyser...or what is left of it. In 1989, the pressure proved too great and it exploded outward. It's now a gentle pool.

After leaving the elk, I didn't get very far before I saw my first bison. So big and beautiful! This one was just casually moseying down the road, and didn't think much about the cars. It wouldn't be the last bison I would see that day.