The San Marcos River is a spring-fed river in the Texas Hill Country, about 30 miles south of Austin in the city of San Marcos (Hays County). Fed by more than 200 springs at its headwaters in Spring Lake, the river maintains a constant temperature of approximately 72°F year-round — making it one of the most popular tubing destinations in Central Texas regardless of season. The water is exceptionally clear, and the springs that feed it are among the largest in the western United States. Archaeological evidence at the Spring Lake headwaters shows continuous human habitation dating back approximately 12,000 to 13,000 years, making it one of the oldest known continuously occupied sites in North America.
Where to Tube
There are two main tubing sections on the San Marcos River, each with a different character. The in-town float runs through San Marcos City Park and Rio Vista Park in the center of town. This section is shorter (roughly 45 minutes to an hour depending on water levels) and passes through the small rapids at Rio Vista Dam — a fun feature that creates a mild whitewater chute popular with both tubers and kayakers. The out-of-town float runs from the southern edge of San Marcos downstream through the countryside toward the community of Martindale. This section takes approximately three hours and is quieter, with more natural scenery and fewer crowds.
Outfitters and Prices
Three main outfitters operate on the San Marcos River. Lions Club Tube Rental (170 Charles Austin Dr, San Marcos) handles the in-town float. Tube rental is approximately $25 per person with unlimited shuttle service back to the start, or $15 per person if you bring your own tube. This is a nonprofit operation — proceeds support Lions Club charitable programs. It has been running since the 1970s and is open daily from roughly May through September.
Texas State Tubes (1001 Aquarena Springs Dr, San Marcos) is the most popular outfitter for the longer downstream float. Tube rental runs approximately $30 per person (includes shuttle), with discounts for military, students, teachers, and first responders (~$20), and reduced rates for children 7–12 (~$10, life jacket required). Children 6 and under float free with a required life jacket.
Don’s Fish Camp (107 River Lodge Ln, Martindale) offers the longer downstream float as well, with float passes around $30 per person ($19 if you bring your own tube), including shuttle and parking. Don’s also has riverside campsites, tent camping, and cabin rentals — making it the best option if you want to combine tubing with an overnight stay on the river.
You can also tube for free by bringing your own inflatable and using public access points at San Marcos City Park, Rio Vista Park, or other riverfront parks. No outfitter is required for the in-town section if you have your own tube and do not need shuttle service.
Rules and Regulations
The San Marcos River has specific rules enforced by the city. Fines for violations can exceed $500.
No glass containers. Glass is prohibited on and near the river. Use cans or reusable containers. No styrofoam. Styrofoam coolers, cups, plates, and other styrofoam products are banned from the river. Single-use container ban: San Marcos has implemented a ban on single-use drink containers on the river. Bring reusable cups, bottles, and containers — anything you could put in a dishwasher. Coolers must have secure lids (zipper, velcro, latch, or bungee). Maximum cooler size is 30 quarts. No jumping from bridges, dams, trees, or cliffs. River depth varies unpredictably and jumping injuries are among the most common on the river. No alcohol on parkland — you can drink on the river itself (in approved containers), but not on dams, spillways, bridges, or in parks along the banks. Pack out all trash. Bring a mesh bag or small trash bag to collect waste during your float. There are also trash receptacles (converted small boats) positioned on the river in some sections. Life jackets are required for children under 8 when river flow exceeds 500 cubic feet per second, and strongly recommended for all non-swimmers at any flow level. When flow exceeds 1,000 cfs, tubing is prohibited.
What to Bring
Water shoes or secure sandals (not flip-flops — they will come off in the current and the riverbed is rocky). Reef-safe sunscreen (the San Marcos River feeds into the Guadalupe River and eventually reaches the Gulf of Mexico, and the river itself is home to endangered species including Texas wild rice and the San Marcos salamander). A hat. Plenty of drinking water in reusable containers. A waterproof bag or dry bag for your phone and keys. A small mesh bag for trash. Sunglasses with a retainer strap. If bringing a cooler, keep it under 30 quarts with a secure lid.
Protecting the River
The San Marcos River is one of the most biologically significant waterways in Texas. Its spring system supports several threatened and endangered species, including Texas wild rice (a plant that grows only in this river), the San Marcos salamander, the fountain darter, and the San Marcos gambusia. Do not uproot or pull at river vegetation (often mistaken for seaweed — it is likely Texas wild rice). Do not chase, grab, or disturb turtles, birds, or other wildlife. Stay in the main channel and avoid trampling the riverbanks, which are vulnerable to erosion from heavy recreational use.
When to Go
Tubing season runs roughly from May through September, though the 72°F water makes floating possible year-round for those willing to brave cooler air temperatures. Weekends from Memorial Day through Labor Day are the busiest — expect crowds, long waits at outfitters, and competition for parking. Arriving before 10:30 a.m. on weekend days is strongly recommended. Weekday floats are significantly less crowded and offer a more relaxed experience. July is the peak month. Check river flow conditions before heading out; during periods of very high flow (above 1,000 cfs), tubing is not permitted for safety reasons. During drought conditions, the shorter in-town float may be very shallow.
Camping Near the River
Don’s Fish Camp in Martindale offers riverside tent sites, RV hookups, and cabins directly on the San Marcos River — it is the closest camping option to the tubing route. Several additional campgrounds operate in the San Marcos and New Braunfels area along the Guadalupe and Blanco Rivers. If you are driving from Austin, San Marcos is approximately a 45-minute drive south on I-35.
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