Buffalo Bayou is a tidal stream that extends from just west of Katy, Tex., to its mouth on the San Jacinto River at Lynchburg. It runs through downtown Houston and is home to numerous parks along its banks. The watershed was important in early Texas history with many settlements forming along its shoreline, and the Port of Houston formed at the confluence of Buffalo and White Oak Bayous. In the 20th century when Houston overtook Galveston as the main port in Texas, Buffalo Bayou was widened and dredged to form the Turning Basin for the Houston Ship Channel. Its uses and location have presented numerous preservation and environmental challenges, and groups such as the Buffalo Bayou Preservation Association and the Buffalo Bayou Partnership.