Mastodon bones discovered in Michigan backyard

One man's backyard project led to a discovery of mammoth proportions.

Eric Witzke was having a pond dug behind his Michigan home. But instead of dirt the contractor stumbled upon the remains of a prehistoric beast.

The 42 massive bones were from a 37-year-old male mastodon between 10,000 and 14,000 years ago.

The creatures are distantly related to elephants and weigh about 5 tons.

Witzke plans to keep a few of the bones but donate the rest to a museum.