I don't have the groundhogs, instead I have their evil cousin the rock chuck. Though, they both have similar behaviors.
This time of year whenever I step outside of my office I glass the back hill. Dang chucks get in there and dig there way to china. Occasionally, they dig a burrow into the canal and it causes problems, mainly flooding.
Anyway, on Tuesday I glassed the hill and there was a chuck at about two hundred yards out on a rock. I went back into the office grabbed my rifle and shooting sticks set up on the deck ready to take the shot and the darn thing had disappeared already. I spent all of 12-15 seconds getting gear and setting up and poof! Gone just like that. Haven't seen the rascal since, but I'll keep looking.