McKinney Falls State Park is organised around Onion Creek and two waterfalls crossing limestone shelves. The channel has carved edges, pools and polished surfaces that change with rainfall and flow.
The falls reveal how water follows fractures and changes in rock level. Riparian woodland, exposed roots, sediment and shaded areas surround them.
Trails connect slopes, channels and drier woodland. Vegetation changes with water availability and soil depth.
The park combines geology, hydrology and forest landscape. Its distinctive quality lies in concentrating limestone waterfalls and riparian ecosystems within a natural area close to Austin.