Need to rid property of Ground Hogs, any ideas

http://www.varmitgetter.com/VarmitGetter.php

http://www.rodexindustries.com/index.html

http://www.rodenator.com

If you want to kill them, and don't want to sit waiting with a gun, buy a conibear trap. This is the type of trap that they will have to crawl thru, and sits inside the hole, or near the entrance. When they crawl thru, the trap will trigger, and whammo!
Don't forget to fasten the chain to a steel rod driven into the ground.
I can't believe that this hasn't been suggested yet.
clove

Not very nice but effective
Cover all the holes , take your lawn mower .
remover the muffler. install a section of pipe and flexable exaust pipe ,
put the flexable pipe down one hole and start the mower, let it run for 30 minutes to and hour . this works for prarie dogs too and moles .
if you deside to snipe them with a rifle I suggest one with a bit more umph than a standard 22lr .