There are no woodchucks or prairie dogs around here, but as I've stated in several other posts, my wife and I have been acting as the official ground squirrel "exterminators" over on our friend's ranch for the last month or six weeks. We've been spending 2 or 3 hours over there a couple of times a week, and up until this week, it's been fairly steady shooting (1 shot every couple of minutes) with our .22LR rifles. However, we were over there for a few hours last Monday, and the grass is getting too tall, making the ground squirrels hard to spot. Besides that, on Monday the wind was blowing really hard, and it was gusty, so we had a hard time hitting the ground squirrels if they were any more than 40 or 50 yards out.
We didn't mind. My wife and I have sort of totaled it up, and we figure between us and our oldest grandson (who went ground squirrel shooting with us once this spring) we've killed close to 500 of the little vermin. And even though we're starting to feel kinda "bloody" if you know what I mean, we've hardly dented the overall ground squirrel population on our friend's ranch.
To answer your question though, most of the ground squirrels we've shot this spring have been between 10 and 100 yards out. Sometimes foolish ones would pop up out of their holes no more than 10 feet away though, and as long as we moved slowly, they would stand there and look at us - like they were trying to figure out what we were. We would sometimes shoot those with our handguns - my wife with her Ruger Bearcat, and me with my Glock 44.
We learned a little trick last year - if we stand still and emit 4 or 5 short, high-pitched whistles, ground squirrels will sometimes pop up out of their holes real close to us. Then, like I say - as long as we move slowly, they'll often stand there and look at us.
Both my wife and I also have .22-250s. On our first morning of ground squirrel shooting, I used my .22-250 to shoot a ground squirrel that was a little over a hundred yards out. But as soon as I shot, I thought, "Man, that was stupid! That was a whole lot of noise and expense just for killing a ground squirrel when there are hundreds of them running around within 50 yards of us."
I have no inclination of ever getting rid of my .22-250 though - it's still a good coyote rifle. And I used to use it for rockchucks (yellow-belied marmots), along with the .223 I used to have as well. I don't usually shoot rockchucks nowadays though. They mostly live on rocky, non-agricultural land anyway, so they usually don't do a lot of damage. If I catch one in the garden eating our freshly sprouted pea plants though... But then again, the .17HMR standing by the back door works just as well on a rockchuck at 30 yards as a much louder .22-250.