Since 1986, bearers of a National Park Passport have been able to get their passport books stamped at park visitor centers and ranger stations. These cancellation stamps are a great way for NPS enthusiasts to chronicle their experiences…unless you’ve only recently found out about them, as we did in 2010 after having already traveled to a number of National Parks and Monuments!
Thankfully, a new iPhone app has just come out to fulfill the same purpose. Not only does it provide information on all current NPS sites, it lets you know which ones are close to you through GPS, and also allows you to record all your visits, past and present, and shows them all on a map: