Fly Fishing the San Marcos River: Spring Fed Bass Heaven
Photo by Lael Johnson
Spring is one of the best times of year to be on the San Marcos River, and right now in April it is prime time. The bass are aggressive, the water is crystal clear, and the river is at its most beautiful — cypress trees fully leafed out, limestone bluffs, and fish that have been stacking up all winter just waiting to eat.
Here's everything you need to know about fly fishing the San Marcos this spring.
What Makes the San Marcos River Special
The springs that create the San Marcos River are the 2nd largest in the state of Texas. The San Marcos Springs on the Texas State University campus push out around 100 million gallons of water a day at a consistent temperature year-round. Drought, heat waves, cold fronts — conditions that shut down other rivers barely affect the San Marcos. If you want to guarantee a good day on the water, this is the river to be on. That consistency also means the fish are healthy, well-fed, and present in good numbers no matter when you show up. There's no off season on the San Marcos.
What You'll Catch
The San Marcos holds one of the most diverse freshwater lineups in Texas. Largemouth, smallmouth, and native Guadalupe bass are all present, along with Guadalupe/smallmouth hybrids that are some of the hardest fighting fish in any Texas river. On a typical full day float you can realistically catch five or six different species — Guadalupe bass, largemouth, Rio Grande cichlids, multiple sunfish species, carp, catfish, and gar will all eat a fly on the right day.
For trophy bass hunters, the San Marcos consistently produces some of the largest bass we see all year. The combination of constant flows, abundant food, and relatively light fishing pressure means fish here have everything they need to grow big.
Why April Is Prime Time
April is one of our favorite months on the San Marcos. The pre-spawn and spawn bass bite is in full swing, which means fish are shallow, aggressive, and actively feeding. This is when we see our biggest largemouth of the year — fish in the 4 to 6 pound range are showing up regularly, and they are not shy about eating a fly. Topwater action is at its best right now. Early mornings especially, a popper or foam bug worked along shaded banks and undercut structure will get violent strikes. If you've never caught a big Texas bass on a topwater fly, April on the San Marcos is the experience to have.
Afternoons when the fish move off the shallows, a Clouser Minnow or streamer stripped through the deeper pools will produce fish all day long.
How We Fish It
The San Marcos is almost impossible to wade fish effectively — the river is too deep and overgrown in most stretches to cover good water on foot. Floating is the way to go, and we run all our trips in stable, comfortable whitewater rafts perfect for two anglers and a guide.
Most of our trips cover the stretch between the towns of San Marcos and Fentress — a beautiful run that hits a wide variety of water types including fast riffles, deep pools, undercut banks, and gravel flats. Our guides know every productive inch of this stretch and will put you in position for the best shots of the day.
Full day and half day float options are available. For anyone traveling from out of town, pairing the San Marcos with a Colorado River day or a Llano River trip makes for an outstanding Texas Hill Country fly fishing weekend.
What to Bring
All equipment is provided on guided trips — rods, reels, flies, and everything else you need. Just bring your Texas fishing license, polarized sunglasses, sunscreen, and comfortable clothes you don't mind getting a little wet. April weather in Texas can be warm by afternoon so light layers are ideal.
For those bringing their own gear, a 5 or 6 weight rod with a floating line is the call. Have both a topwater setup and a streamer ready — you'll want both.
April Dates Are Going Fast
Spring is one of our most popular times of year on the San Marcos and dates fill up quickly. If you want to get on the water this season, don't wait.
Book your San Marcos River trip here.
All Water Guides is Austin's premier fly fishing guide service and the 2025 Orvis Outfitter of the Year. Our team of expert guides covers the San Marcos River, Colorado River, Guadalupe River, Llano River, and Texas coast year-round.
