I need help

We're in upstate Montana visiting our daughter and the neighbor has a huge problem with ground squirrels. I have never hunted them before so I could use some help.

First, the conditions. The area is flat unmowed grassland. The mounds are everywhere. Along the drive, in the drive, and of course littering the field. The temp has dropped from the 90s into the 70s with overcast skies. Of course the squirrels see us first and chirp warnings to the others. I'm thinking early morning parking the truck in the drive and shooting from the bed.

Our equipment consists of my son in laws .22 NP2 and my .177 HW100BP-K sighted in at 50yrds with 10.5gr Mako slugs.

Those of you who regularly hunt these pests, how would you proceed?
 
Boscoe is correct.

Sounds like these are prairie dogs?

I spend about two weeks during the late spring hunting PD's in Kansas and Colorado and have done so for the last five years. I've tried several techniques. The most successful was when I would go out and sit in the middle of the town on my swivel camp stool rifle braced on shooting sticks creating a 360 degree field of fire. In your case, sit back to back so no one is in the crossfire.

50 yards will be a little tough but you should be able to whack a few. My experience is, at that distance, they are not as brave as they are at 75 and beyond. 

Know at that range, they typically will just barely put there head up out of the burrow. Gotta look for their eyes as they may not be barking or yiping and just observing you. 

Them knowing you are there isn't a bad thing; actually a good thing. They feel compelled to warn the others of your presents and the yips and chatter will help you locate them. When they would quit alerting the others, I'd get up and move toward another part of the town. They'd quiet back down but fifteen minutes later, they be back to the chatter. Early morning (7-8am) is what we've found to be the best time. During the heat of the afternoon, they go back down into the burrow and siesta. 

Like Boscoe said, it's a game of patience. 

As for the weaponry, something in the PCP category, preferably at least 22 and shrouded preferred. (i.e. Marauder etc.) 

Good luck and have fun!
 
First, make sure it's legal to shoot out of the vehicle. When I shoot them at my permission, I'm there early and I set up before they come out of the ground. I use a tripod, as I'm shooting out to 75 yards sometimes. They don't all come up at the same time and you have a better chance of getting more of them as soon as they pop up, rather than driving up on them when they are all out. Be patient and try to keep movement to a minimum. Good luck and have fun. As an added note, California ground squirrels are known the harbor the fleas that carry bubonic plague. When I shoot them I don't handle them, I just leave them where they were shot. I don't even get close enough to take photos. You might want to check the local wildlife office to see if they have issued any warnings. Be safe
 
Truly ground squirrels or prairie dogs? If you can find or build a little "hide" just show as little of yourself as possible & be patient & wait. Check your poi's at 50-75 yards so you know exactly where to aim & you'll be ready to shoot fish in a barrel (or ground squirrels in a yard). Have fun! Be careful, the ground squirrel THWACK can be addictive. 
 
Just took my first ground squirrel at 47 yards. I could barely see its head, but the 10.5gr Mako slug it it and sent it dancing. Unfortunately it fell into its hole. The Tactacam captured the action and when we return home I'll edit all the footage.

p.s. these aren't prairie dogs or whistle pigs. it's my understanding pds don't live this far north. (30 miles south of the Canadian border)

I've been wacking the reds hard as they have been stripping the sapplings of their bark.

my .22s are in storage so the .177 is all I have for now.
 
I've been hunting CA g.s. for 40 years all with air rifles. They could be ground squirrels but more than likely they are prairie dogs that far east. .177 is on the light side for hunting them but you can be effective with proper shot placement. 1st rule of shooting critters that live underground "They are everywhere and they are nowhere" all at the same time one minute it's a shooting gallery and the next hour could be nothing at all but they are still all around you most likely even looking at you. 

If you have no natural cover or shade then the best idea is to get a blind something like this would work great (https://www.sportsmansguide.com/product/index/guide-gear-deluxe-4-panel-spring-steel-hunting-blind?a=1878705) and set it up the evening before about an hour before it gets dark since they will mostly be down by then. When hunting park well away from the hide at least a few hundred yards and then walk into it. Have your hunting chair and cooler with plenty of water and something to eat and then have at it!

They mostly detect movement and light changes (shadows) since raptors are their main predators if you can be someplace where they don't detect movement you should be able to get some. A blind should shorten the "spook distance" the distance at which they run and hide when they detect movement so on open grassland (which I don't hunt) hiding yourself and your movement is key.

Good luck!
 
Well I met the owner and he is a well known actor. I won't mention his name as he is very genuine and gracious enough to let us shoot his property. He greeted us and showed us his Gamo that he has been using. The temps have dropped into the 50s and the sky is cloudy. Later in the week the temp is predicated to return to the high 80s and the sun will reappear. We're here for several weeks so I'm sure we'll have plenty of chances at them.

We did see quite a few while sitting in chairs in the pickup bed. Thinking of building a screen for it to hide behind.
 
Living in WA I'm assuming this is what he's shooting at. We have lots of these here.

Screenshot_20210810-103417.1628616892.png

 
I love this gun. I re-sighted in again today for 75 yards and the groups haven't grown from the original 50 yard sight in. It gets a bit heavy when in the woods all day, but a single point sling would cure that. Eventually I'm going to mount an MTC Viper Connect and put the Tactacam and Arken back on the DS Regal. That should lighten it up a bit.