McKinney Falls is a 641-acre park features over 80 campsites, including developed (RV) and hike-in sites. Screened shelters, group shelters and a group dining hall are also available. Outdoor recreation opportunities include hiking, mountain biking, bicycling, swimming, birding and wildlife observation. Onion Creek, which flows 1.7 miles through the park, offers both swimming and fishing opportunities.
https://www.austintexas.org/listings/mckinney-falls-state-park/2895/