Illinois Valley Chamber of Commerce, helping bring together the local community. Founded in 1940, the chamber has long been the "Unity in the Community" of the Valley. Cave Junction lies in the heart of the Illinois Valley, and is the "gateway" to the World Famous Oregon Caves National Monument. En route to the coast via Grants Pass off of I-5 this valley is home to some of the most beautiful mountain views around, and boasts the gorgeous Illinois River, known for its fishing, intense rafting, and serene setting.