West of Austin, in the Texas Hill Country, Hamilton Creek pours over a limestone lip and drops about 15 m (50 ft) into a pool beneath a vast, half-collapsed dome of rock. Hamilton Pool Preserve is one of the most photographed natural swimming holes in the United States, and with a little planning it makes a superb half-day trip.

Hamilton Pool Preserve in Travis County, Texas
Hamilton Pool Preserve in Travis County, Texas.

How Hamilton Pool formed

The pool is a collapsed grotto. Over thousands of years, water flowing along Hamilton Creek wore away the limestone beneath a rock shelf until the roof of an underground river gave way. What remains is a deep box canyon with a semicircular overhang arching over the water, and the creek still spills over its edge as a waterfall that rarely dries up completely. The pool's level stays fairly steady even in droughts.

Below the grotto the creek runs about three-quarters of a mile further before it joins the Pedernales River. Large limestone blocks around the pool are pieces of the old roof, and rockfall from the cliffs is still an ongoing hazard, which is why the path beneath the overhang is now closed.

Hamilton Pool Preserve, Texas – second view
Hamilton Pool, a collapsed limestone grotto in the Texas Hill Country.

History of Hamilton Pool Preserve

People have used this canyon for a very long time: cultural remains in the area date back more than 8,000 years, and the Tonkawa and Lipan Apache lived here before the 1800s. The pool takes its name from Morgan C. Hamilton, who owned the land in the mid-1860s; his brother Andrew Jackson Hamilton, later governor of Texas, is said to have visited the grotto.

In the 1880s the Reimers, a family of German immigrants, bought the property for sheep and cattle ranching, and around the turn of the 20th century they began opening it to the public for recreation. Heavy use and overgrazing took their toll. Travis County bought 232 acres from the Reimers in 1985 and designated Hamilton Pool a nature preserve in 1990, after which the damaged ecosystem was restored.

Wildlife and plants of the preserve

Walk down to the pool and you pass through two worlds. The uplands are semi-arid juniper and oak savannah with native grasses; the canyon floor is shady, damp and green. Several rare plants grow in the canyon, including canyon mock-orange, red bay and the chatterbox orchid.

The preserve is also home to the endangered golden-cheeked warbler, a songbird that nests only in central Texas, along with many other birds. Hamilton Pool forms part of the Balcones Canyonlands Preserve, a network of more than 31,000 acres of protected habitat for endangered species around Austin.

Visiting Hamilton Pool: reservations, fees and swimming

The preserve sits at 24300 Hamilton Pool Road, Dripping Springs, and is run by Travis County Parks. The essentials:

  • Reservations are required every day of the year, booked online. Each covers one vehicle and up to eight people, for a morning (9:00 am to 12:30 pm) or afternoon (2:00 pm to 5:30 pm) slot.
  • Fees: a $12 online reservation fee per vehicle, plus entrance fees paid on arrival in cash only: $8 per adult, $3 for seniors aged 62 and over, and free for children 12 and under.
  • The trail from the parking area to the pool is about a quarter of a mile, steep, narrow and rocky, with uneven steps. Allow around 30 minutes for the round trip and wear sturdy shoes.
  • Swimming depends on bacteria levels and recent rainfall. When it is allowed, only part of the pool is open, there is no lifeguard and the water can drop below 10 °C (50 °F) in winter and spring.
  • Bring your own drinking water. There are no concessions, electricity or running water, only portable toilets and picnic tables. Pets, drones, glass containers and alcohol are not allowed.
Hamilton Pool Preserve, Texas – third view
Hamilton Pool Preserve, west of Austin.

Check the Travis County page for the current swimming status before you go; even when the pool is closed to swimmers, the grotto, the waterfall and the canyon walk are worth the trip. For more Texas Hill Country water, read our Jacob’s Well guide, or travel further for Pongour in Vietnam.

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