Visible from the air? Air you planning to require a rescue?
By the way folks...I was out today...conditions are very interesting.
Most holes have a thick layer of ice over top of them...but it's not enough to support a Jeep. We broke through every single hole we tried - and the ice is thick enough to be an obstacle.
Also, the snow is slippery, and the temperatures have been high enough that the ground isn't frozen - expect mud as well as snow.
Please be cautious out there...things that were easy in the summer required a winch today