Interstate Highway 10 exits the urban and industrial areas east of Houston and crosses two floodplains—one created by the San Jacinto River and a wider, swampy one that contains numerous lakes associated with the Trinity River. The northeast extension of Galveston Bay is Trinity Bay, which is really a bay within a bay; complex sediment patterns are discernible in both. Brown, oval Lake Anahuac is just south of Interstate Highway 10. Brighter reflective features show concentrations of petrochemical industries along the Houston Ship Channel and Texas City.