Hamilton Pool Preserve was designated a nature preserve by the Travis County Commissioner's Court in 1990. Located 3/4 mile upstream from its confluence with the Pedernales River, Hamilton Creek spills out over limestone outcroppings to create a 50- foot waterfall as it plunges into the head of a steep box canyon. The waterfall never completely dries up, but in dry times it does slow to a trickle.
With over 450 plant species, some of which are rare and endemic, this tract of land is incredibly diverse in both floral and faunal species.
Hamilton Pool Preserve is a part of the Balcones Canyonlands Preserve (BCP). The BCP encompasses more than 31,000 acres of endangered species habitat owned by Travis County, the City of Austin, The Nature Conservancy, the Lower Colorado River Authority, Travis Audubon Society, and private landowners.
The preserve is critical habitat for the federally endangered, Golden-cheeked warbler, as well as over 170 species of both resident and migrant avian species.
Hamilton Pool is located in the vital Central Flyway zone. Bi-annually, birds follow this route as the migrate between their nesting and wintering grounds.
The diverse vegetation of Hamilton Pool ranges from semi-arid species in the uplands to riparian species in the canyon. The uplands of the preserve are a juniper and oak savannah with a variety of native grasses and wildflowers. Several rare plant species including canyon mock-orange, red bay (western-most colony of this eastern species), and chatterbox orchid are known to occur in the canyon areas along Hamilton Creek.
A unique natural area surrounds this pool, collapsed grotto and canyon, formed by thousands of years of water erosion. Lush plant communities, a variety of wildlife species and natural shelter attracted the area's first inhabitants. Cultural remains date back over 8,000 years.
In the 1880's, the Reimers, an immigrant family from Germany, bought the property to raise sheep and cattle. Legend has it that their eight-year-old son discovered the collapsed grotto.
Although ranchers might have considered the grotto a safety hazard for their livestock, the Reimers soon realized its value as a recreational area and opened the property for public use. Around the turn of the century, only a handful of people had the transportation to come out and enjoy the cool, serene surroundings.
By the 1960's, and on into the 1980's, Hamilton Pool's popularity had soared, as visitors packed the legendary swimming hole. The land suffered from sheer numbers and few restrictions.
In addition to the impact from the visiting public, cattle, sheep, and goats grazed the delicate ecosystem for several decades, resulting in changes to the native vegetation.
In 1980, the Texas Parks and Wildlife Department cited Hamilton Pool as the most significant natural area in rural Travis County. In 1985, Travis County purchased 232 acres from the Reimers family and implemented an aggressive land management plan to restore Hamilton Pool.