Enos Abijah Mills (1870–1922) was an American naturalist, author, and homesteader who became known as the “Father of Rocky Mountain National Park.” Born in Kansas, Mills was a sickly child with a severe digestive ailment, likely celiac disease. At age 14, his doctors suggested that the mountain air of Colorado might help improve his health. He traveled alone to the Estes Park region and settled near Longs Peak, where he fell in love with the mountain wilderness. Over the course of his life, he would climb the peak more than 300 times, becoming a skilled guide and self-taught expert on the area’s flora and fauna.

A chance meeting with famed naturalist John Muir in 1889 profoundly influenced Mills, inspiring him to dedicate his life to conservation. Returning to Colorado in 1902, Mills purchased and expanded the Longs Peak House, renaming it the Longs Peak Inn. The inn became a hub for outdoor enthusiasts, where Mills would lead excursions and give popular lectures on nature. His writing, which included books like Wild Life on the Rockies and The Story of a Thousand-Year Pine, helped popularize the region’s wilderness among a wider audience. Mills also pioneered the field of ”nature guiding,” training and certifying guides in a way that is still practiced by the National Park Service today.