The Hyde Park specimen is an American mastodon (Mammut americanum), probably an older adult male (30-40 years old) that may have weighed as much as 10,000 - 15,000 pounds (4,500 - 6,800 kg) when alive. It lived approximately 11,500 radiocarbon years ago. There is a chance that Native Americans laid eyes on this animal when he was alive, though there is no evidence to indicate that humans had any direct impact on its death. Mastodons are extinct relatives of modern elephants which branched off the elephant family tree around 15 million years ago. Mastodons were numerous and widespread in North America up until around 10,000 years ago, when they became extinct together with many other species of large mammals at the end of the last glacial period.

After excavation, the bones of the Hyde Park Mastodon were shipped to the University of Michigan Museum of Paleontology, where a scientific-quality cast was be made of the skeleton. There, they were studied by vertebrate paleontologist Dr. Daniel Fisher, a leading authority on mastodons in North America.

The Hyde Park Mastodon was shipped to a company in Alberta, Canada, to have an armature built for mounting the bones. The skeleton has been on display at PRI’s Museum of the Earth since September 2003.