Amethyst Mountain facts for kids

Amethyst Mountain is a tall peak in Yellowstone National Park. It stands 9,609 feet (2,929 m) high. It's part of a long ridge in Park County, Wyoming. This ridge is between the Lamar River and Deep Creek. The ridge includes Specimen Ridge, Amethyst Mountain, and the Mirror Plateau. The closest town is Silver Gate, Montana, about 19 miles away.

In 1872, explorers named it Amethyst Mountain. They found beautiful amethyst crystals there. The mountain is famous for its many amethyst and opal crystals. It also has amazing petrified forests that you can visit. The Specimen Ridge Trail goes over the top of Amethyst Mountain. This trail also passes through the Yellowstone Petrified Forest.

What is Amethyst Mountain Made Of?

Amethyst Mountain is mostly made of a rock layer called the Lamar River Formation. This layer is over 440 feet (130 m) thick here. It has a lot of conglomerate rock. It also has some tuffaceous sandstone and siltstone.

Conglomerate rock is made of many different sized pieces. These pieces are often stuck together by mudflows, called lahars. Lahars are like fast-moving rivers of mud and volcanic debris. Other parts of the conglomerate were laid down by ancient rivers.

Most of the petrified wood and buried tree trunks are found in these conglomerate layers. Smaller pieces like fossil leaves and pollen are in the sandstone and siltstone. These rocks formed along riverbanks or in old river channels. All these rocks on Amethyst Mountain came from volcanoes. They were eroded and washed down from nearby ancient volcanoes.

Yellowstone's Amazing Petrified Forest

One of the most special things about Amethyst Mountain is its petrified forests. These are ancient forests that turned to stone. They are found in the Lamar River Formation on the mountain's slopes. This area is known as the Yellowstone Petrified Forest. Scientists have studied these forests for over 130 years.

Some of these ancient forests were buried where they grew. This happened when volcanic mudflows (lahars) covered them. Other petrified trees were carried by rivers and lahars from higher up the volcanoes. They were then buried in new places.

Scientists have learned a lot about how these forests became petrified. For a long time, people thought they were buried by volcanic ash. But now we know that many trees were moved by mudflows and rivers. This is similar to how trees were buried by the 1980 eruption of Mount St. Helens.

It's very important to remember that collecting fossils in Yellowstone National Park is against the law. Visitors should always stay on marked trails to protect these special places.