Relay For Life is Saturday, May 4 Mercer Island High School will host the annual 24-hour Relay for Life event on Saturday, May 4, at the high school’s track. May 1, 2013 2:19 pm Mercer Island High School will host the annual 24-hour Relay for Life event on Saturday, May 4, at the high school’s track. The event is a fundraiser for the American Cancer Society. Learn more at www.mirelay.org.