Upper Geyser Basin, Main North Area
The Upper Geyser Basin is considered the main attraction for most visitors. This massive thermal area contains hundreds of thermal features, including world famous Old Faithful. It is located at the end of the road reached by taking the Old Faithful Interchange. We split this geyser basin into two sections, the area south and east of the footbridge over the Firehole River near Castle Geyser, and the area north and west of the bridge. This is the northern section, starting from the bridge and heading north.
Grand Geyser is the largest regularly active geyser in the world. Its interval is normally about eight hours. Eruptions often exceed 200 feet. We have not been lucky enough to see it, yet, so the picture at left is of the cone area.
Beauty Pool is a hot spring with the classic color rings. Blue colors dominate the hot center, with darker greens and browns around the cooler edges.
Chromatic Pool is right next to Beauty Pool, and is linked to it. As the water level of one rises, the other one drops.
After the path crosses another bridge on the Firehole River it soon comes to Giant Geyser. It erupts infrequently, but when it does it is one of the largest, reaching 250 feet in height. The enormous cone often splashes over, as seen to the left.
Just as the boardwalk reaches the paved trail is Grotto Geyser. It has a large and unusually shaped cone. Its eruptions reach 15 feet and can last up to 15 hours.
Riverside Geyser is on a side loop to the right. This geyser shoots out at an angle over the Firehole River. The average interval between eruptions is six hours, and can last up to 20 minutes. This is another one we have yet to see. Its cone on the river is shown to the left.
Morning Glory Pool
Morning Glory Pool lies at the end of the paved trail. This pool is the poster child for the effort to keep people from vandalizing the thermal features. It used to be a deep blue color and was widely considered the most beautiful pool in the park. Unfortunately, people threw literally tons of coins and other debris into it. This clogged the vent and lowered the temperature, resulting in the dark green and brown color of today.