Elementary Level: Prehistoric Animals in Washington

  • Posted 3/03/2014
  • HistoryLink.org Essay 10746
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Over the past thousands of years, many varieties of mammals lived in what is now Washington. Several important fossils of prehistoric mammals have been discovered in different parts of the state. (This essay was written for students in third and fourth grade who are studying Washington State History and for all beginning readers who want to learn more about Washington. It is one of a set of essays called HistoryLink Elementary, all based on existing HistoryLink essays.)


Dinosaurs flourished during the Mesozoic Era, between 63 and 230 million years ago. The climate at that time was much warmer and vegetation grew easily. This created an environment that was good for the giant lizards. However, no dinosaur fossils have been found in Washington. Dinosaur fossils have been found in Oregon and Idaho so it is believed that dinosaurs probably did live in what is now this state.

More than ten thousand years ago, the Ice Age Floods caused great changes to the land. They washed away much of what lived or existed here -- including dinosaur remains.

After the Mesozoic Era, creatures called mammals spread across the earth. Mammals are warm-blooded creatures with large brains and hair. They give birth to live babies instead of hatching them out of an egg, and care for their young after birth. Many varieties of mammals lived in what is now Washington over the past thousands of years. Several important fossils of prehistoric mammals have been discovered in different parts of the state.

Palouse Mammoth

In 1876, Benjamin Coplen was a homesteader on Hangman Creek south of Spokane. His property had a spring where his cattle went to drink fresh water. Near the spring was a marshy area called a bog. It was filled with sticky mud like quicksand. Sometimes the cattle would wade in the bog and get stuck. Coplen and his brothers were curious. What else might have gotten stuck in the bog? They took a long pole and began to feel along the bottom of the swampy pit. Suddenly they struck something hard.

Even more curious, they attached a hook to a pole and began pulling up bones. The brothers were farmers and so they were familiar with most farm-animal bones. But some of the bones were very large and they had never seen anything like them before. They could not identify what animal they had come from. They decided to drain the bog to see what else they could find.

The Coplen brothers found many more bones plus what they thought were huge horns. They decided to show off their unusual discoveries by displaying the bones and horns in nearby towns. A man who viewed their exhibit took photographs of the Coplens' discoveries and sent them to an expert at Yale University. The scientist believed they were not horns but tusks from a mammoth.

Coplen and his brothers were very excited and went home to see if they could find more of the mammoth's remains. They did find more bones and more tusks -- a total of twelve! They soon set out on another road trip to show off their amazing mammoth fossils.

Meanwhile, Ben Coplen's neighbors, William and Thomas Donahoe, wondered if they could have such bones on their property too. They drained a bog on their land and, sure enough, they also found bones and a huge skull. They thought they might be able to make some money if they took their finds to the Walla Walla County Fair. They were disappointed that they did not become rich from their mammoth bones so they sold them.

The Donahoe bones had several owners before they found a safe permanent home at the American Museum of Natural History in New York. Scientists studied them carefully and they were able to learn many important things about the mammoths that lived in this part of the United States.

In time, the Coplen brothers sold their bones to the Chicago Academy of Sciences. The museum took all the bones and assembled a skeleton. What they did not have, they made of plaster. The skeleton was 13 feet high. It was exhibited at the World's Columbian Exposition in Chicago. The mammoth skeleton now is on display at the Field Museum of Natural History in Chicago.

Blue Lake Rhino

In 1935, four friends were exploring a cliff in Jasper Canyon, which is located north of Soap Lake, Washington. Mr. and Mrs. George Peabody and Mr. and Mrs. Haakon Friele were looking for petrified wood. They came upon a small cave and went inside. They were excited to find pieces of bones scattered on the ground. They also found part of a jaw with teeth. They felt the jaw was important and wanted scientists to look at it -- so they took it with them. George Beck of the Washington State Normal School was very interested in the fossil and decided to visit the cave himself.

What Beck discovered was that the cave itself was actually something very special. More than 14.5 million years ago, a rhinoceros died in a shallow lake. The body turned over and floated upside down in the water. Over time, it filled with air and gases and grew larger and larger. Sometime after the death of the animal, molten rock flowed into the water. Layers of the lava formed layers around the body of the animal and preserved the rhino's form. The cave is actually a mold of the rhino's body.

Scientists continued to study the fossil mold. They made a plaster cast of the inside of the mold to use as an exhibit at the Burke Museum in Seattle. Museum educators thought the best way to display the mold was to make a copy of the cave. They felt this would be the most interesting way to tell the story of the Blue Lake Rhino. It is thought to be one of the most unusual fossils in the world.

Sea-Tac Giant Sloth

Gordon Simmons worked for the Sellen Construction Company. In 1961, his company was working on a runway for the Sea-Tac Airport, south of Seattle. A deep hole for a lighting tower had been dug when Simmons spotted bones sticking out of the ground. Digging was immediately stopped and experts at the Burke Museum were contacted.

The ground was very wet. As the scientists dug, the sides of the hole kept falling in. But they were able to find many bones that were in very good shape. Sixty percent of the bones that they found made up the body of what was identified as a giant sloth. Researchers were not sure if it was a male or a female.

This was the first and only fossil of an extinct sloth to be found in Washington. Scientists decided that the Sea-Tac sloth lived and died sometime between 12,600 and 12,760 years ago. This time period was soon after Ice Age glaciers melted. The environment was perfect for many different types of vegetation to grow -- a great place for large herbivores or plant eaters.

The giant sloth's scientific name is megalonyx jeffersonii. It was named in honor of President Thomas Jefferson, who loved natural history. He had studied many sloth bones that had been dug up in Virginia. The president was especially excited by the claws. He thought that they might have belonged to a very large lion or tiger. He wondered if it could still be living in the parts of the country that were not yet explored. Over the years, further research proved that the creature was not in the cat family but was a giant sloth.

The Sea-Tac sloth is on display at the Burke Museum. In order to display it as a whole skeleton, experts had to make some of the missing bones from plaster. One of the missing pieces was the head, but an exact copy of a giant sloth's skull was donated to the museum.

Sequim Mastodon

In 1975, Emanuel and Clare Manis moved from California to Sequim, Washington. They hoped for a more simple life. They wanted to have a huge garden and a few cattle so they could support themselves. They decided that their small farm needed a permanent pond so they could have water for their crops and cows. Emanuel Manis picked a spot in a marshy area on his property for the pond but he had to wait until the ground was dry enough to dig. The summer of 1977 was very hot. By the end of August, the conditions were ideal to start the pond project.

Manis used a backhoe to help clear the bog for his pond. After he had pulled out several old logs, he and Clare thought they looked unusual. They realized that the logs were actually tusks! They continued to search and found other interesting bones. They contacted archaeology experts who confirmed that the tusks, other bones, and a tooth were from a mastodon. The damp ground had preserved them for 13,000 to 14,000 years. Because the water in marshes and bogs is usually very still, things that are submerged under the surface do not move very much. They are excellent places to find fossils and sometimes entire skeletons.

Manis's pond was going to have to wait. The Washington State Office of Archaeology and Historic Preservation was given special money to continue studies at the site where the tusks were found. In addition to scientists, more than 50,000 curious people visited the small farm.

Experts determined that the mastodon was very old when it died. The tooth was very worn down. Some of the bones showed that the animal had arthritis. They think that the animal died of old age, disease, or drowning. By cut marks on the bones, they also were able to see that the body of the mastodon had been cut up for food.

One of the most exciting discoveries of all was a strange point sticking out of one of the bones. The scientists thought that it might be the broken tip of a hunter's spear. That could prove that humans had lived in the Pacific Northwest for much longer than had been thought.

The idea that humans had hunted at the time that the Sequim mastodon died led to disagreements between different groups of scientists. In the 1930s, stone points used in hunting had been found in Clovis, New Mexico. Until this new discovery in Washington, the Clovis people were thought to be the earliest hunters in North America. Researchers who believed in the Clovis theory said that the Sequim mastodon had been injured in a fight and the point in the bone was from the tusk of another mastodon. Finally advanced scientific analysis showed that the object was a piece of mastodon bone that had been made into a spear point.

The tusks and major bones of the mastodon are on display at the Museum and Arts Center in Sequim. The tusks have been placed in a tank of water in the exhibit to keep them from further decay.

Moxee Mammoth

On May 10, 2001, construction workers in Moxee, Washington, were preparing the ground for a new parking lot. Steve Herke was driving the earthmoving machine when he noticed something that looked strange. It was a tusk! Herke knew it was something special. Work stopped so the ground would not be disturbed any further. Archaeologists from Central Washington University and Yakima Valley Community College were contacted to check out this exciting discovery.

Even though it was early spring, the weather was hot and dry. The workers did not realize that the tusk needed to be protected from the heat once it was uncovered. Being buried in the ground had actually sheltered and preserved it. Experts from the Yakima Valley Museum arrived five days after the tusk was uncovered. In those few days, the top layers of the tusk had begun to crack. The point of the tusk had almost turned to powder. But they were still able to learn a lot about the animal by testing the tusk.

At first they thought the tusk was from a mastodon. They discovered that it was actually from a Columbian mammoth -- which is a distant relative of the modern-day elephant. Adult mammoths were about 12 to 14 feet high at the shoulder and weighed between 8 and 10 tons. The mammoths were grass-eating creatures that lived in the open plains. They lived in the Northwest for about 400,000 years. These creatures became extinct about 10,000 years ago.

For more than a year, experts continued to dig at the site. They found a few more bone chips but no more traces of a mammoth. Scientists decided that the mammoth did not die in Moxee. They believe that after it died, the body of the mammoth was washed down into the valley by an Ice Age flood. The tusk was found in an area that often backed up when water from melting glaciers was trying to squeeze through Wallula Gap. As the water slowly went down, rocks, sand, dirt, and animal bodies were left behind. Each time a glacier dam burst and water rushed down toward Wallula Gap, the same thing happened. Experts found six different layers of flood deposits above where the mammoth tusk was buried. This shows that the Ice Age floods had a great influence on the Yakima Valley. There have been twelve other mammoth finds in the Yakima Valley.


This essay is based on the following HistoryLink essays: "Benjamin Coplen discovers mammoth bones on Hangman Creek in May 1876" (Essay 7512), "Climbers find basalt mold and bones of a 15-million-year-old rhinoceros at Blue Lake, Grant County, in July 1935" (Essay 9409), "Construction at Sea-Tac Airport unearths an extinct giant sloth on February 14, 1961" (Essay 9408), "Emanuel Manis finds mastodon tusks in Sequim, on August 8, 1977" (Essay 8511), and "Ice Age mammoth tusk is discovered at Moxee on May 10, 2001" (Essay 8496). It is one of a suite of essays (called HistoryLink Elementary) that focus on important people, places, and events in Washington State History, and that align with elementary school textbooks and state academic standards. All the HistoryLink Elementary essays are included in the HistoryLink People's Histories library, and the HistoryLink Elementary suite and related curricular activities can also be found on HistoryLink's Education Page (http://www.historylink.org/Index.cfm?DisplayPage=education/index.cfm). The HistoryLink Elementary project is supported in part by Heritage 4Culture's Special Projects Program.

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