ESCAPE FROM ALCATRAZ TRIATHLON: Test your endurance with some incredible athletes. Don your wet suit for a chilly 1.5-mile swim from Alcatraz Island, a rigorous 18-mile bike ride out the Great American Highway from the Marina Green through the Presidio and back then 8-mile run to Baker Beach and back to the Marina. If you're serious about pumping up and competing, meet at Marina Green to register at 11 a.m.
FAULT WALK: Walk the line -- the San Andreas Fault line, that is. Lace up your comfy hiking shoes and grab your camera and a bottle of water for a 2-mile guided tour along the fault with a park ranger. Explore the earthquake zone plus local geology and natural history. Meet at the Sanborn County Park Ranger Office at 5 p.m. Call 408-867-9959 if you have questions.
WALK FOR CHARITY: Help raise awareness and money for research to help make a difference for people with psoriasis and psoriatic arthritis through the National Psoriasis Walk for Awareness. Gather at Justin Herman Plaza at 8 a.m. to register for either a 1K or 5K walk.