SAN MARCOS – The San Marcos Historical Society and the city present Rockin’ Through Decades, 4-7 p.m. Aug. 10 at Walnut Grove Park. The dance party, featuring The Fabulous Mardels, will feature dance contests, games and a scavenger hunt. The free event celebrating they city’s 50th anniversary is open to all ages. More information online: www.ci.san-marcos.ca.us/index.aspx?page=234.