Otto was hired as the Monument's first custodian, in which capacity he earned one dollar per month until leaving the post in 1929.

According to Horace Albright, "Otto was a marvelous guide and knew every inch of his monument, which he tended like a personal kingdom.

[4][5] 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.

[4] Born in Marthasville, Missouri, he married Beatrice Farnham on June 20, 1911, at a rustic altar near the base of Independence Monument in what is known today as Wedding Canyon.

[6] Otto lived his final twenty years on a mining claim near Yreka, California, where he was buried in a pauper's grave.