Kaufman and Trinity soils contain over 60 percent clay in the control section. Heiden, Houston Black, and Ferris soils are on uplands. Frio, Gowen, kaufman, Trinity, and Whitesboro soils are on similar flood plains positions. Flooding occurs one or more times each year for 2 to 7 days duration unless protected. Cleared areas are in pasture or planted to crops of cotton, corn, oats, or grain sorghum.
Native vegetation is hardwood forests of elm, hackberry, pecan, oak, and ash.
Mainly in Texas along tributaries draining Blackland Prairie soils. Moderately extensive with a total of about 30,000 acres. These soils were formerly included in the Trinity and Frio series. High Shrink-swell properties and cracks that are 0.5 to 1 inch or more wide at a depth of 12 inches or more during dry periods.