The remains of the extinct relative of the elephant turned up during a July pickup in Grand Rapids, a local newspaper reported. The tooth pieces and tusk are estimated to be anywhere from 12,000 to 15,000 years old. The Christian charity, called In The Image, turned the find over to the Grand Rapids Public Museum, which is adding them to its collection.
"I'd love to find out where this was from and the history behind it," said Jay Starkey, the charity's director.
The tooth is broken into two parts and is covered in lacquer. A tusk, also covered in lacquer, is hollow at one end and also may be from a mastodon.
The animals roamed North America more than 10,000 years ago, and their remains turn up from time to time in Michigan - usually buried underground. The museum already has a number of mastodon bones and the new additions will be available for loan to educators for use as a learning tool in schools.
"This is kind of an oddball way for something to come in," said Tim Priest, collections manager.
For the charity, the discovery is one of many odd donations to come in. Drugs are a common find, Starkey said. It once got a painting worth about $5,000 that ended up being donated to the museum. And it also has received an urn with someone's ashes inside.