Found this in sylmar, CA back in 1988.
Approx age 30,000.
Was working on a residential housing project when the backhoe operator dug up the entire jaw the tooth was found later in the day by me.
The layer of soil that the mastodon was found in was consistent with the massive flood and sediments that flowed through this area 30,000 yrs ago. A young mastodon that was caught in the flood waters.
A trench was being dug from the house out to the street for electric and was about 3' deep. The track of homes was near the base of a mnt bluff. Fragments of the mastodon were scattered in front of the home and left there. No one really seemed to care that much.At the end of the work day I walked over to the trench and kicked a dirt clot and underneath was the tooth, I thru it in my lunch box. The people living there now have no clue there is a buried mastadon in there front yard.