2006 Off-road Rear Diff Lock Question

So yesterday I was lucky enough to go into a snow covered ditch and get stuck... I tried to engage my rear diff lock and the light just blinked. I had it in 4Lo, tried the button in park and neutral; but nothing. I have been reading that there is an actuator and I am wondering where it is/what it looks like. I have a feeling, if it is possible, I may have snow packed in that area and maybe it can't move.
I did it right when I ditched the truck, passenger side had snow up to the windows, high-sided the front end, articulated the rear suspension and high-sided it. A couple other trucks stopped to try to pull me out but they just about got stuck also...I dug snow for ~2.5 hrs and finally had to get pulled out by a tow-truck.