GVHS Athletics Great Valley High School is a member of the PIAA (Pennsylvania Interscholastic Athletic Association) and is subject to the guidelines and principles set forth by this governing organization. Locally we are a member of the CHES-MONT League and PIAA's District One. Great Valley offers 19 varsity sports for students in grades 9-12. Great Valley also offers a Middle School Athletic Program. Use the links on the left to obtain further information on Great Valley Athletics.