This is an incredible crawler course and very very inspiring, thank you for sharing all your hard work with us, and the knowledge.
I do have a couple of questions:
1) How did this hold up to the hurricane this past summer with all the rain?
Since the Port mix was just a cap, and you mentioned the possibilities of cavities under the cap causing issues.
2) Paint, what kind of paint did you use, and how was it applied, and/or isn't there a dye you could mix in with the process as well?
3) Herbicide, what are you doing to control weed/grass growth on your course, I'm either using a product from Tractor Supply, or a mix of Round-Up and diesel fuel.
You're on a couple hours from me, as I'm right out side of Austin, so your ground being clay, is very much like my own back yard, and since the wild fires in 2011 here, the debris of trees is pretty common to get a hold of, rock on the other hand is a bit of a struggle, though I can go and purchase that of course.