What’s a little #SundayFunday without some adventure? These 1929 horseback riders took to the East Rim Trail in Utah’s Zion National Park. Today, trail visitors with a permit can still hike through a ponderosa pine forest, take in scenic canyon views, and end at a seasonal spring.

Zion National Park is just one of many areas that the National Park Service maintains. We’re celebrating #NPS100 all month with historic photos, videos, and posters that are now held at the National Archives. The Act to Establish a National Park Service is currently on display in the National Archives Museum in Washington, DC.

Image: “Horseback party on East Rim Trail showing Yellow Pine (Pinus brachyptera),” 9/12/1929.