You wanted answers?? Here are your answers straight from the source:

"The snow stakes are young maple trees. We use maple because they do grow straight and have limited branches on the trunk. They stay flexible during the cold months and don't break off when the snow and slush hit them. We generally get around 18,000 per year or so from a couple of different sources. The best stakes are around 7' - 8' tall and no more than 3/4" in diameter. Each driver is responsible for his own plow route and it takes 1 - 2 days to put them in. The back local township roads take more than the state highways because of curves, hills, and the narrower lane widths typically found on those roads. This practice has been going on since they first started plowing with trucks at both the county and state level. The stakes help the drivers see where the edge of the road is during major storms when it is snowing and blowing and they also let the drivers know how far back the snow banks can be pushed when they start to extend out into the road."
~~~~Thanks to B.D. at the Chippewa County Road Comm.

Now you know, and knowing is half the battle.............