White River formation South Dakota. My guess is femur, it's large. Very heavy. Weighs almost 10 lbs. I am having a hard time finding long Bone examples of some of the large mammals that lived in SD. Would love some help with an ID. Thanks so much
Very Nice Find! Good Luck with getting an ID. If someone on here doesn't come up with an ID, send some pictures to a university near where it was found.