9. Sequoia & Kings Canyon National Parks – California
These neighboring parks are filled with towering trees, steep cliffs, and deep canyons—and they’ve seen dozens of fatal accidents. From 2014 to 2019 alone, 23 deaths occurred due to falls, many after visitors ignored warning signs or left designated paths.
In several cold cases, hikers vanished while exploring remote areas with no clear explanation, even after intensive search efforts.