The Most Hard-to-Get Swimming Spot in Texas Sits Under a Collapsed Grotto with a Waterfall

Hamilton Pool, Texas

Just outside Austin, Hamilton Pool rocks that sweet spot between swimming hole and natural wonder. This limestone grotto, carved out over thousands of years, comes with its own 50-foot waterfall and emerald pool. Sure, you need a reservation these days, but scoring Texas’s best natural pool is worth the extra effort.

It Started as a Family Ranch

Hamilton Pool Preserve covers 232 acres in western Travis County. It used to be part of a massive 3,600-acre ranch owned by Morgan C. Hamilton in the mid-1860s, and it quickly became a favorite swimming spot for early settlers. Travis County bought the land in 1985 from the Reimers family to keep developers away.

Formed When a Cave Roof Collapsed

The pool formed thousands of years ago during the Holocene epoch when the roof of an underground river collapsed. This created the grotto and canyon area that makes the place so unique.

Look up and you’ll see limestone formations, including stalactites and ledges seeping through the rock. The distinctive shape and structure make it a prime example of Texas Hill Country’s karst topography.

The 45-foot Waterfall Changes with Rainfall

The real showstopper at Hamilton Pool has gotta be the 45-foot waterfall pouring over limestone into the jade green pool below. Sometimes it’s barely a trickle, other times it’s roaring depending on the rainfall (quite common in the Hill Country). Years of flowing water and erosion have smoothed the limestone underneath into curved shapes.

Native Tribes Used the Pool

Before white settlers showed up, Hamilton Pool was home to the Tonkawa, Apache, and Comanche tribes. They relied on this water source during dry spells. Archaeologists found stone tools and pottery scattered throughout, indicating the area was used as a campsite for over 8000 years.

No Swimming Due to Bacteria

Don’t pack your swimsuit without checking first. Despite what you might think, swimming at Hamilton Pool is a hit or miss – and often a miss. The Travis County Parks closes it whenever rain causes high bacteria levels or when conditions get dangerous.

Flash floods tear through after heavy rain, and there aren’t any lifeguards watching over you. For example, in 2024, swimming was allowed only about half the time, with closures occurring on 95 out of 199 days from January to July. Always check the website before driving out there or you might be disappointed.

Fish & Mountain Lions Live Here

Hamilton Pool Preserve is part of the Balcones Canyonlands Preserve, which protects over 31,000 acres of habitat. Foxes, bobcats, porcupines, skunks, deer, and possums call this place home. Watch where you step cause there are snakes too, including water moccasins.

Bird watchers love this place since its part of the Texas Hill Country Birding Trail. Cliff swallows are frequently seen nesting along rocky outcroppings near the grotto. Just ask for the bird list at the entrance booth. The preserve is also home to white-footed mice, sunfish, carp, and numerous fish species.

The Rare Golden-Cheeked Warbler Nests Here

Hamilton Pool is one of the last places where endangered golden-cheeked warblers build nests. Endemic to Texas, nearly one-third of the population has disappeared between 1999 and 2011.

They fly up from Central America each spring to raise families in the Hill Country. As development eats away their habitat, places like Hamilton Pool become even more important.

Rare Plants Also Thrive Near the Pool

The preserve’s ecosystem includes rare plant species such as canyon mock-orange that grows in the limestone and rocky soils of canyons and slopes. In spring, Texas bluebells add vibrance to the vista while bigtooth maples, in some of the more protected areas of the preserve, splash the landscape in deep gold. Parts of Hamilton Pool also include a rare plant species called Limestone Milkwort.

Falling Rocks Are a Real Hazard

Hamilton Pool won’t let anybody swim this summer or anytime soon, because falling rocks have been a significant hazard since Winter Storm Uri in 2021.

They’ve also closed the trail section underneath the overhang, but you can still see the pool and waterfall from safe areas.

The Trail Leads to the Pedernales River

The trail from Hamilton Pool Preserve to the Pedernales River is approximately 1.8 miles round trip (0.9 miles each way). The beach area and massive rock overhang provide plenty of shady spots to relax.

There’s a moderately challenging three-quarter-mile trail through the canyon alongside the creek that’s usually open. Hit the pools near Milton Reimers Ranch (charges $5 per person). If you visit both parks on the same day, you can score a discount on the second entrance fee.

Make It a Full Day Trip

Hamilton Pool sits about 23 to 30 miles west of Austin. The drive typically takes about 45 minutes under normal traffic conditions.

Open daily from 9 AM to 5:30 PM, hours might change seasonally. Entrance runs $8 for county residents, $15 for everyone else, and kids under 12 get in free. The parking fee is a separate $12.

Bring water and good shoes (amenities at the preserve are just bathrooms and a few picnic tables). After you’re done, check out the nearby Westcave Outdoor Discovery Center for an educational tour.