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. 

The preserve is home to the Golden-cheeked Warbler and a great variety of other birds. 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.

Hamilton Pool Preserve is a part of the Balcones Canyonlands Preserve. 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 BCP represents a regional effort to balance protection of endangered species habitat with economic development.

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.