A self-professed trailbuilder described as a "benign but enthusiastic eccentric", Otto arrived in Grand Junction, Colorado in 1906, helped construct a municipal waterline between Pinon Mesa and Fruita, Colorado, and acquainted himself with the neighboring topography. In 1907, Otto wrote, "I came here last year and found these canyons, and they felt like the heart of the world to medical I"m going to stay and promote this place, because it should be a national park."
Because of his efforts to promote and protect the area, others took notice, and by 1909 the local newspaper was lobbying to make the area a national park.
On May 24, 1911 the area was designated Colorado National Monument.
Otto was hired as the Monument"s first custodian, in which capacity he earned one dollar per month until leaving the post in 1929. He was often dubbed "The Trail Builder" or "The Hermit of Monument Park" in newspaper and magazine stories, and was rarely seen without his two burros (named Foxie and Cookie) laden with camping equipment and provisions.
They divorced in 1912. Otto lived his final twenty years on a mining claim near Yreka, California, where he was buried in a pauper"s grave.
In 2002, the Colorado National Monument Association erected a gravestone carved using a sandstone rock resembling Independence Monument.