Yeah, ours isn't a trap-and-relocate ground squirrel problem. The house we live in sat empty for a while. We inherited a whole slew of problems from that, not the least of which is an enormous and well-established ground squirrel population.
We've been fighting them for years. My guess is there are 3-4 colonies. At least one is deeply rooted under the house, we're actually worried about what they're doing to the foundation but that's another post.
The squirrels also attract snakes, hawks and other predators that would happily take a hen. That's why we're trying to construct a coop that's as predator-proof as possible.
As ChicksnMore suggested, another option is to create a cinderblock base with HC on the bottom, fill it with dirt/sand/mulch, and construct the coop on top of that.
That sounds simpler than renting a jackhammer from Home Depot to dig down two feet (I actually kind of want to try that because I'm weird, but jackhammering 300 cu ft of caliche is probably a
lot more difficult than I think).
For those who have built a cinderblock base above the ground and a coop on top of it, do you have drainage issues? During a monsoon does it get water logged? We get brief but very heavy downpours. Would it trap a lot of water sitting right on caliche?
Also, did you use mortar? And how did you connect the HC to the cinder blocks?