Need Help Id'ing Bones

[mds1075]

My son and I were at a creek nearby our home in Allen Co (NE Indiana) yesterday doing some rockhounding and panning, and I came across the big bone in the front of the picture just laying on the creek bank about 95% exposed. I suspected right off the bat that it wasn't anything wild of recent, given whitetail deer is the largest thing in this area and I've field dressed enough of those to know.

I wanted to see if there was anything else and started digging behind the spot where it was laying and we found about 30 more bone fragments/pieces, including the almost full intact vertebrae pictured. This was all in a 1'x2' dig. Now, we had a record spring rainfall and this creek was out of its banks for more than a month this year, but we were finding bone fragments a foot into the bank and this was about 7' down from the top of the creek bank.

If you're not familiar, this area was the Black Swamp area after the Wisconsin glacier, just until as recent as a few hundred years ago when they drained it off for farmland, and the original Great Lakes once had southern shoreline just about a mile from here. Boy, did the Native Americans love leaving their field points all along it. Anyways, I researched bones for comparison some last night and the closest that I could come up with was bison, or a stretch as Cervalces, the stag-moose. And I all but eliminated domestic cow and horse, but I could be wrong. Mastodon have been found in this county, but this seems way too small for that. No dinosaurs have ever been discovered in Indiana, to my knowledge.

I'm hoping to get some answers to this, as we're planning on going back to dig more in the site this weekend. But I don't want to spend the time digging if it's some farmers missing cow from a hundred years ago. I can post additional pics/angles, if needed. Thanks!

[mds1075]

Here are a few more pics. I managed to find two of the processes for the vertebrae, which I'm assuming is a lumbar, in the fragments that I had. I also see now two pelvic sections from different animals, likely same species.

Thanks!

Matt