Well see that is the thing...my guy is new to trails...and spooks at rocks. I want to know if it is a rock or something I SHOULD not make him trot past.
Trust your horse. Chances are, they will know a snake is across the desert trail before you could react. And as mentioned, I'd bet when they felt the hoof beats heading towards them, they'd scoot off the trail / road. On a full moon night, you would not need any light, to be able to see the ground well.
