The Clearwater Festival, one of the country’s largest annual music and environmental celebrations, returns to Croton Point Park this Father’s Day weekend, June 15 and 16. Founded in 1966 by the late folk singer and activist Pete Seeger, the Clearwater Festival was inspired by his mission to clean up the Hudson River. It raises money for the Hudson River Clear¬water sloop and organization, which provides environmental research, education and advocacy to help preserve and protect the river and its tributaries. This year, the Clear¬water Festival, also known as the Great Hudson River Revival, marks Seeger’s centennial birthday and the 50th anniversary of the flagship with diverse music, dance, educational and family-friendly programs.