Norris Geyser Basin is the hottest hydrothermal area in Yellowstone National Park. It features a large number of impressive geysers, hot springs, mud pots and fumaroles like no other area in the park. The world's tallest geyser, Steamboat Geyser, is in Norris Geyser Basin. Unlike most other geyser areas, the water in Norris is very acidic and the smell from fumes emitted can be quiet strong.
The two major areas to explore are - Porcelain Basin and Back Basin. Both are accessible via maintained loop trails (sometimes uneven). There are many large and small, prominent and unnamed geysers across the basin. These are some of the features that can be easily spotted from the boardwalk.
Porcelain Basin Trail:
A 1/2 mile, boardwalk and rough uneven loop trail, offers views of some interesting and colorful features of Norris Geyser Basin (part of the loop was closed). It begins with panoramic views of the basin and then runs through a steaming landscape of geysers and hot springs.
It was named so because it emerged on Valentine's Day in the year 1907. It has rare eruptions of up to 30 feet high, but constantly puffs up dense steam.
Constant Geyser is one of the larger geysers of Porcelain Basin. It is a frequent performer with intervals of minutes to few hours.
Somewhat close to the boardwalk is the colorful Whirligig Geyser. It has had periods of complete dormancy in the past but is currently active with an interval of several hours. Its eruption cycle begins with a sudden filling of the crater progressing into an eruption. Whirligig's run-off channels display the growth of colorful thermophiles.
Solfatara is a fumarole rich in Sulfur. This hillside is venting sulfuric acid, gases and steam. Scalding mud and steam are often barely covered by hot, crumbling, decomposing rock, making it a very dangerous landscape.
Congress Pool is a perfectly round geyser with milky greenish water. It is more noticeable for its changing water levels than for its eruptions.
Porcelain Springs is named after the milky colored mineral deposits found here. This is the fastest changing area of Norris Geyser Basin. Geyserite is brought to the surface by hot water and forms a sinter sheet over this flat area as the water flows across the ground and the mineral settles out.
Sunday Geyser is a quiet blue pool. Its last recorded activity was in the early 1980s.
Scummy Pool is named for the appearance of its water. It is muddy and sometimes bubbling.
Back Basin Trail:
A one and half mile loop trail winds through wooded area and some of the world's best geothermal features. The trail can be rough, steep and uneven. There is a shorter 1 mile loop trail that covers most of the features in the basin.
Emerald Spring, named for its emerald color, is the first feature to see on Back Basin trail. Bubbling activity seen is mostly due to emission of gases and steam, and rarely due to boiling water.
Steamboat Geyser is the world's tallest active geyser. Its major eruptions are infrequent and unpredictable with long periods of dormancy lasting even decades. When it does have major eruptions it can reach up to 400 feet high. The last recorded major eruption occurred in September 2014. Steamboat has frequent minor eruptions which involves splashes of 10-40 feet high.
Cistern Spring transformed from a quiet, dark pool to a milky blue hot spring. Its run-off waters have killed surrounding trees and the deposits have created small terraces on one side of the pool. Empty pool during Steamboat Geyser's major eruptions indicate that there is a subterranean connection between the two.
Black Pit can be seen close to the boardwalk on the way to Echinus Geyser. It has hot acidic has greenish-gray water or sometimes dark black water.
Sulphur Pot is on the opposite side of Black Pit. It is a small pool with almost clear blue acidic water.
Echinus Geyser is the largest active acid geyser in the world. The brick red color of this geyser is due to high percentage of iron oxide and other metals. Although it was a frequent performer and the only predictable geyser at Norris Geyser Basin in the past, it is mostly dormant now.
Crater Spring is a bluish-green pool with hot acidic water and geyserite ledges around its crater. It is a mostly quiet pool with some steaming and overflowing activity.
Tantalus Geyser is a quiet geyser with occasional splashes. Run-off channels of Echinus and Steamboat Geysers travel through Tantalus Geyser.
Mystic Spring is a milky blue pool surrounded by geyserite. It has weak activity involving boiling, overflowing and sometimes splashing.
This unnamed hot springs contains hot acidic water.
Vixen Geyser has a small vent surrounded sinter deposits reddish-brown in color due to high percentage of iron-oxide. Vixen erupts almost continuously every few seconds to an hour. Major eruptions last up to an hour and can reach 30 feet high.
Yellow Funnel Spring:
This spring has a fairly symmetrical funnel shaped basin. It was once a very attractive colorful pool, but in recent decades, it has been dry or barely filled with water.
Named for its shape, Porkchop geyser used to be a quiet geyser with occasional eruptions. In 1985, it started erupting from a small vent and did not stop until it exploded many years later. Now it rarely erupts, sometimes years apart.
A few feet from Porkchop Geyser, the Second Erupter often sends out angled jets of hot water.
Double Bulger Geyser:
It is a small continuously active geyser.
Pearl Geyser is an attractive milky blue color pool. Any activity is rare and can vary from steaming to overflowing spring to small splashing.
Area East of Pearl Geyser:
Some disturbances few years ago caused changes in the appearance of this area, creating new smaller vents and blue pools.
Tantalus Creek is the main drainage in the Back Basin. Much of the water in these creeks is geyser run-off and is very acidic.
It is a small circular pool surrounded by geyserite. This feature can occasionally overflow and have small splashing eruptions.
Veteran Geyser is a frequently active multi-vent geyser surrounded by whitish-gray geyserite. Its eruptions reach 25-50 feet high.
Palpitator Spring is a small circular geyser. It has small geyser eruptions that reach about 3 feet high. Prior to and during an eruption, the water bounces causing ripples to occur over the surface of the pool, and slightly overflows.
It is a small, dark, circular pool over 20 feet deep. Its activity limits to boiling in the center of the pool.
Monarch Geyer Crater:
After Steamboat Geyser, Monarch was most notable geyser in the past. it is an irregularly shaped pool with pale blue-green water. Major eruptions were recorded until 1913, followed by only minor eruptions in the later years.
It is a milky blue-green pool with slightly bubbling and acidic water. Its run-off merges with Monarch Geyser's run-off channel and drains into Tantalus Creek.
In the past, Minute geyser erupted very frequently up to 60 feet high. One of its vents was blocked by rocks and other trash thrown by early visitors, and the rocks were completely sealed by geyserite. Its smaller vent shows some activity of steaming and small spouts.
It is a steam vent surrounded by weathered, whitish-gray geyserite. In the past this vent had some eruptions up to 30 feet high.