“Grand Canyon National Park has thousands of structures and hundreds of miles of roads, and it’s a lot to take care of,” said Chris Lehnertz, the park superintendent in 2018. (File photo by Jordan Evans/Cronkite News)WASHINGTON – A former superintendent at Grand Canyon National Park warned Monday that if the park stays open during a government shutdown, understaffing could put “nationally important, irreplaceable resources” at risk. Grand Canyon National Park drew 4.9 million visitors last year, according to the park service. In Death Valley National Park, campgrounds remained open but bathrooms were unattended and closed, causing sanitation problems. In Zion National Park, a visitor graffitied their social media tags on a rock located in Angels Landing.