The Brazos River plays a lead role on the geology of the Upper to Middle Texas Coast. Brazos sediments have a distinctive red color and are chiefly clay. The aerial photo on the left shows the Brazos discharging suspended red clay into the Gulf of Mexico in 2004. The right figure shows the Brazos River, its drainage basin, and Triassic red beds in NW Texas. These 200 million year old red beds supply red clay to the Brazos River. Because of their distinctive color and clay-rich character, ancient Brazos sediments can easily be identified along the coast.