Here in East Central Illinois I have found one shed from this year( the largest Shed in the pic) so far this year a few weeks ago. The other 2 sheds in the pic I found in the last couple of days and they are from last year. The earliest sheds I have found around here was in late January a few years ago.
I have found over 40 sheds and pickup racked skulls in the past , I like to use binoculars as an aide to save me alot of uneeded steps and keying in on travel trails, bedding areas, food sources, fence crossings , creek and river crossings...... I have found some of my best sheds by searching in pine and evergreen patches and bedding areas.... seems the deer like these pine areas to escape the cold winter winds and snow especialy if it is located close to a food source.