Killeen sits west of the Balcones Escarpment, on the Grand Prairie and Lampasas Cut Plain side. The Texas Almanac splits Bell County exactly this way: Blackland Prairie in the east, Grand Prairie in the west, with soils here described as light to dark, loamy and clayey with limy subsoils and shallow stony soils in places.
In practice that means thin soil over Lower Cretaceous limestone on the uplands. The dominant series on this ground hit indurated limestone somewhere between about 11 and 40 inches, so depth to rock typically runs one to three and a half feet and varies block to block.
The clay is not absent, it is just in different places. Deeper clay soils with prominent shrink-swell cracking occupy stream terraces and valley floors, which means a property down in a draw can behave completely differently from one up on a ridge two streets away.
The other thing that shapes work here is housing turnover. Killeen’s owner-occupied rate is only 49.5 percent, the lowest of any city on our list. That is the statistical signature of a large rental stock and high turnover next to Fort Hood, and it means a lot of flatwork has been repaired rather than replaced for years.