Did you know the National Park Service is offering 10 free entrance days during 2017 to celebrate its 100th birthday? Or that you can buy a Federal Recreation Pass for a mere $80, allowing you and three others an entire year of free entry to all the country's national parks, forests, and wildlife refuges? Or that a handful of museums have free entry on certain days, or have "suggested" admission prices, such as the Metropolitan Museum of Art in New York City? Cha-ching — can you say amazing money savers!?
I would also suggest taking advantage of online resources, such as TripAdvisor community forums, to scope out even more good deals. Sites such as this one will open your eyes even wider on how to save money at each destination. Just as with planning your route ahead of time, being in the know and researching ongoing deals — even the ones not publicly showcased — will allow you to get the most bang for your buck.