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The River, the Springs & the Rules

San Marcos, Texas

Things to Do · Events · Local Guide
San Marcos · The River · Martindale
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About San Marcos

San Marcos — a Spring-Fed College Town

San Marcos sits on I-35 between Austin and San Antonio, where the Edwards Aquifer surfaces through roughly 200 spring openings at the bottom of Spring Lake and forms a river that holds 72°F year-round. It is the second-largest spring system in Texas, after Comal Springs at New Braunfels, and it has never stopped flowing. The upper stretch is federally protected habitat for eight threatened and endangered species — which is why the river has rules. Texas State University and its 44,000 students set the town’s rhythm; the river is why anyone is here at all.

Founded
1851settled at the springs; Hays County seat
Known for
The river72°F year-round, spring-fed
Location
Hays County seaton I-35, Austin↔San Antonio
Population
67,5532020 census; 44,596 students
Nearby
The springsSpring Lake · Meadows Center
From Austin
~30 miles S~35–50 min via I-35
Read more about San MarcosShow less
About Us

Built by a locally operated Hill Country travel company.

san-marcos.ai is built by Spencer and Jess Forrest, owners of Backroads Hill Country — a locally operated Texas Hill Country travel company that has represented Hill Country vacation rentals since 2001, with thousands of guest stays coordinated across the region.

Most travel platforms flatten a place like San Marcos into generic top-10 lists. This is built the other way around — local knowledge first, from people who actually live and work in the Hill Country.

Spencer & Jess Forrest Backroads Hill Country
The Network

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Local Knowledge

Frequently asked about San Marcos

The river. San Marcos sits on a spring system that surfaces through roughly 200 openings at the bottom of Spring Lake and holds 72°F year-round. It's also a college town — Texas State enrolls about 44,600 students — with a downtown square, the Cheatham Street Warehouse music venue, and two large outlet centers on I-35.
Yes. It's spring-fed from the Edwards Aquifer, so air temperature barely affects it. In February the water is warmer than the air. The springs have never stopped flowing in recorded history.
Reusable drink containers only in the river and along the banks — those are the "No Zones." Disposable containers like cans and bottles are allowed only in designated "Go Zones" set back from the water. One cooler per person, under 30 quarts. No glass anywhere. No styrofoam anywhere, including foam floats. Rio Vista Park is fenced with staffed entries and a non-resident fee in summer; confirm the current amount before you go.
Because the upper stretch of this river is federally protected habitat for eight threatened and endangered species — including Texas wild rice, which grows in this river and nowhere else on earth. People mistake it for seaweed and pull it up. The rules exist so the river survives being loved.
Two choices. The in-town float runs City Park to Rio Vista Park, about 45 minutes to an hour; Lions Club Tube Rental in City Park is the only outfitter inside city limits. The downstream float starts outside town and runs three to four hours through farmland to Martindale — wider, slower, and much less crowded. Texas State Tubes and Don's Fish Camp run that stretch.
Three natural limestone drops in the in-town stretch. Depth and debris change day to day. If you don't want to go over them, exit the river to the left — there's a portage path. Don't take the falls on a tube if you can't swim, and note there are no lifeguards anywhere on the river.
Weekdays, if you have any flexibility. Summer Saturdays the in-town float is packed and there's a line at Lions Club. March through May and September through October the water is still 72 degrees and the crowds are gone. That's when locals float.
San Marcos doesn't have a resort or a boutique-inn district — it's chain hotels along I-35 serving the outlets and the university. If you want atmosphere, stay in Wimberley (20 minutes northwest) or New Braunfels (20 minutes south) and drive in. Backroads Hill Country can help you find the right fit.