This sounds about right. My mom's property in S. NM is a shale mountain. Where her house sits, she had .. 7? dumptrucks worth of soil brought in (I can't call it "top soil" as it actually was the bed of a dried up pond, so there was a lot of fish yuck in it, but man was it rich soil!!) and took us all summer to spread it around (by hand!!.. literally! Shovels & rakes.. you know how much soil is in a full-size dump truck??
). Gophers were coming out of the woodwork to hit the plants she planted in that soil versus the native soils that have a lot more rocks in it. Me personally, I don't have gopher/vole problems and never had a prairie dog in my yard (they're all over the place here, but I'm lucky!). I do have mice, but trying to trap these boogers as I really don't want mousies in my yard (where or where are my snakes???).