I walked the ravine that pretty much encircles half of our house and was able to get enough sand to fillthe nesting box with about 2 inches of sand. It wasn't the driest stuff but it will eventually and hopefully they will be thrilled with it.
So this ravine is about 150 feet to our north and east. I can stand down in the ravine, look up and see the house. And there, in the sand were the prints from a really big buck.

We could literally sit on our deck with our rifles and watch for him but come Saturday, that deer will disappear into the buck twilight zone, only to reappear the day after rifle season ends and antlerless season begins.