I would have to agree with ColoradoOak. The bull that shed his antlers does look a little sick. That would explain the early shed. The other bulls are still packin' which goes to show that the one that has shed probably has something wrong with him. Elk normally don't shed in Idaho until beginning to mid-April.
Those are some cool photos though. Hopefully you'll find those sheds when they do drop! Good luck!
MuleyCrazed
Idaho