I'd like to see this as a per visitor metric. Like, North Cascades National Park in WA is the least visited park, so it's going to be super low on the death total, where as these get millions of more visitors probably. Also, Lake Mead is a big area that people go not just because it's a park but because they want to go boating and shit, drinking alcohol, and you'd expect more deaths there for those reasons than someone going to just see the scenery in Grand Canyon and such.