Here in my area of SC we are blessed with some beautiful COE parks, coupled with the Senior Pass you can't beat. The State Parks that lease from the COE honor the pass at 25% which is the same discount at 65 years of age. The Senior Discounts very per state , Tennessee doesn't appear to have a Senior Discount (nonresidents) that I can see, but do have a Veteran's Discount of 15-25%. Ohio is another with a resident discount, they appear to honor Passport America(for my limited use 1 to 2 times year) I don't have. It just pays to plan ahead and research each state. My preference is COE, Federal,State Park and Private in that order.