Who was often called the father of our national park system?

John Muir is often referred to as the father of our national park system due to his influential role in the conservation movement and his advocacy for the protection of wilderness areas. His writings and activism were pivotal in the establishment of several national parks, including Yosemite. Muir co-founded the Sierra Club in 1892, which played a significant role in promoting environmental preservation and influencing public policy regarding national parks. His vision for preserving natural landscapes has left a lasting legacy in American conservation efforts.