From I-65, take Cahaba Valley Road (AL-119) exit. Go South on AL-119 and immediately turn left on to State Park Road. Go approximately 1.5 miles to the park entrance. You can reach Peavine Falls by paying your $2 per car fee at the entrance and asking the worker for directions. Peavine Falls is hidden in a back corner of the park, and can be reached by a short walk of about ten minutes down and fifteen back up.
The trail to Peavine Falls is easily accessible for all hikers, however, the last part involves scrambling down a slippery slope to get to the bottom of the falls. Waterproof shorts and river sandals would come in handy once you are at the base of the falls, so that you can position yourself in the runoff to get a dramatic perspective. Expect to get wet trying to get a good shot, I know I did!