Tens of thousands of people are expected to come to UC Davis on Saturday, April 17, for its 86th annual Picnic Day, one of the largest picnics and student-run events in the country. The daylong open house will begin at 9:30 a.m. with opening ceremonies northwest of the Quad between Wickson and Veihmeyer halls, followed by a traditional parade through the campus and downtown Davis. The three parade co-marshals will be Stephen Robinson, a UC Davis engineering alumnus and astronaut; Thomas Duncan, the university's 1998 Outstanding Senior Male Graduate; and Marya Welch, a former UC Davis coach who established the Women's Athletic Association in 1948. Robinson will discuss his space travels at 1:30 p.m. in Room 1100 of the Social Sciences and Humanities Building. A limited number of tickets to the free presentation will be available at the lecture hall beginning at 12:30 p.m., and the doors will open at 1 p.m. Among the Picnic Day features new this year are a climbing wall east of the Silo from 10 a.m. to 4 p.m.; a children's science exhibit presented by the Explorit Science Center outside Hart Hall from 9 a.m. to 4 p.m.; and the "Picnic Day Swing-Out" with big band entertainment as well as dance lessons and demonstrations in Freeborn Hall beginning at 2:45 p.m. Other highlights include: * four chemistry magic shows -- 9 a.m., 10 a.m., 1 p.m. and 2 p.m., front porch of 194 Chemistry Building * the Battle of the Bands -- 2 p.m., lawn Lake Spafford * sheepdog trials from 10 a.m. to noon and a frisbee contest for dogs from 1 p.m. to 4 p.m., both on Hutchison Field, south of Recreation Hall * athletic competitions and exhibitions from judo and rugby to roller hockey and water polo -- throughout the day at various athletic facilities Picnic Day is organized by a 17-member student board of directors and involves about 500 volunteers. Media contacts: Juliet Michelsen, Picnic Day publicity director, (530) 752-6320, jnmichelsen@ucdavis.edu; Julia Ann Easley, News Service, (530) 752-8248, jaeasley@ucdavis.edu.