Starting at Cuero Highway 236 bridge and ending at Victoria City Park, this great race is run over 41 miles of the fastest water on the Texas Water Safari course. Elapsed times for this race at high water can be breathtakingly fast. Finishing positions in the Texas River Marathon, also fondly known as "The Prelim", are used to determine starting positions in the Safari itself, (with one position on each row being set aside for out-of-state teams whose members cannot all make it to Texas in early May.) It is a highly competitive race, while being fun for all concerned.

In addition to qualifying teams for superior starting positions, this event provides racers with the opportunity to see a couple of the only real rapids on the race course. Many racers will traverse the "Nursery rapids" during the night and it can be very helpful to have seen them during the daylight first. As with all TWS sponsored races, Safari rules and classes apply.