The Eastern and Western Cross Timbers are famous geographic landmarks. Mansfield and southeast Tarrant County lie in the Eastern Cross Timbers that extends southward from the Red River through the eastern parts of Denton, Tarrant and Johnson counties and the western parts of Grayson, Dallas, Ellis and Hill Counties.The fifteen-mile band of blackjack and post oak trees formed the margin of the western frontier of Texas until the 1870’s and provided protection from the hostile Comanche and Skidi Pawnee Indians. Cross Timbers oaks are used for firewood, railroad ties, and poles, but the most important function of the timber belt is preserving water. The timber prevents rain water from running off the surface and causes much of it to soak into sands. These sands supply artesian water for hundreds of wells to the east and south of the Cross Timbers.For many years, people in the Mansfield area were said to live “on the prairie” (east of town) or “in the timbers” (west of town).