El Aserradero was the first ever log flume attraction in the world and the fourth oldest ride currently operating at the park, built by
Arrow Development, which later became
Arrow Dynamics. The log flume replaced the 'Burro Ride', which operated from 1961 to 1962. From 1963 to 1968, El Aserradero only operated one flume. In 1968, due to the ride's popularity,
Six Flags added a second flume next to the original, doubling the attraction’s capacity. The park billed the ride as "the most popular and exciting ride ever devised." During the 1970s, Six Flags Over Texas added themed animations along the ride in which
Lumberjacks could be seen sawing logs. Also added was a cover to the drop on flume 2, which later was removed along with the animations. El Aserradero's success inspired many amusement parks around the world to add a log flume of some type. On August 30, 2023, the park announced that the two flumes of El Aserradero would be combined into one, making it one of the longest log flume type attraction in the world. It was also announced that the ride would undergo a new name as El Rio Lento. Quietly, Six Flags Over Texas had removed the announcement and all of any details of the El Rio Lento on their website and at the park, creating rumors of the ride being canceled. The park has not released a statement since the announcement on August 30. ==Ride Experience==