When I pulled off after a bad run on the short course, I noticed that the salt had peeled away from the dirt surface underneath. The salt was about 1/2 to 3/4 of an inch thick at most. It seems I remember people talking about when it was measured in feet, not fractions of an inch.
Also, I noticed that I did not have nearly as much salt accumulating on my bike, trailer, and truck as I did in 2013, I guess this was due to it being much drier this year.