Collin County Sits on the Blackland Prairie — Some of Texas's Most Fertile Soil

The Blackland Prairie runs from North Texas into Central Texas. Its name comes from dark, clay-heavy soil that made the region good farmland. Some of these clay soils swell when wet and shrink when dry. Nearly all of Collin County lies in this region, which the Handbook of Texas calls the richest agricultural region in the state.

That clay can matter around a house. Changes in soil moisture can cause uneven foundation movement, cracks, and other damage. Soil still varies from one lot to the next, so a buyer who sees signs of movement can consider a foundation inspection instead of guessing from the regional map.