Why Tahlequah Foundations Move
Tahlequah sits on the edge of the Ozark Plateau, where limestone and chert from the Boone Formation lie close to the surface. Between the rock there's a layer of clay that soaks up water in a wet spring and shrinks hard in a dry summer. That swelling and shrinking pushes different parts of a foundation up and down at different rates, which is what causes the cracking and unevenness people notice (Vesta Foundation Solutions).
Homes closer to the Illinois River and Baron Fork bottomlands tend to see more of this movement, since the clay there holds extra moisture longer after a rain. It's not a sign something was built wrong. It's just the ground underneath doing what Ozark clay does.