I’m not sure everyone knows about the 4th grade program through the National Park Service.
NPS provides free park passes to all USA 4th graders. Most parks, historic sites and monuments also have Junior Ranger programs where the kids can explore more and earn badges for free.
This is a great value for 4th graders and their families! Check it out!
Every Kid in a Park | Main
This site is run by the General Services Administration for the Department of the Interior's Every Kid in a Park program.