Travel Reference
In-Depth Information
This is a heavily burned area where a 1976 fire left dead trees standing about. After 12
years, when the dead trees had dried out, the 1988 North Fork fire came this way, and a true
firestorm resulted—a popular locale for photographers that summer.
15.5/5.5
For about 0.3 mile (0.5 km) along the road, turnouts are available on the west side
where
Clearwater Springs
are located along Obsidian Creek. The only sign here says “Un-
stable ground— boiling water” for a good reason: visitors have been burned in the hot springs.
Yellow monkeyflowers and microorganisms thrive below Clearwater Springs.
15.7/5.3 Semi-Centennial Geyser
(near the “Obsidian Creek” sign) is now a sometimes
steaming, sometimes scummy pool drowned by Obsidian Creek. But in 1922, the year Yel-
lowstone Park was 50 years old, it sprang to life with a huge explosion, hurling scalding water,
mud, and rocks to an estimated 300 feet (90 m). The expelled material destroyed nearby road-
bed and trees. A few weeks later the geyser had ceased to erupt at all. Semi-Centennial is the
most northerly geyser in the park.
16.0/5.0 Roaring Mountain
and
Lemonade Lake.
You'll find it hard to hear any roaring
now, and only on colder days do you see steam rising from the numerous vents, but the moun-
tain was active and sometimes very loud in the park's first 50 years. The soil is still so acidic
that little grows here. Lemonade Lake is greenish when it has water, but in summer it is usu-
ally dry. An interpretive sign explains how this and other park features change over time, es-
pecially as a result of earth tremors.
16.5/4.5 North Twin Lake
has a lovely green color, particularly in morning sunlight. Its water
may be too acidic for pond lilies.
16.9/4.1 South Twin Lake
has a darker blue-green color, and pond lilies bloom near its
shores. These lakes are twins only in being next to each other and separated by a small piece
of land, being similar in size, and having no fish. They differ in acidity and color. North Twin
Lake is very acidic (pH 3.5), since it receives most of its water from Roaring Mountain, per-
