William Gladstone Steel, born September 7, 1854, in Stafford, Ohio, was the youngest of ten children born to William and Elizabeth Steel. The family moved to Kansas in about 1864, and then traveled across country to Oregon in 1872.

William Steel dreamed of visiting Crater Lake, which he had seen pictured in a newspaper as a child. After seven years of searching, he found someone who had seen the lake, but it was not until 1885 that he made his first expedition in person. Crater Lake was so compelling to Steel that he vowed to have it designated as a national park. After seventeen years of relentless advocacy, he succeeded during President Theodore Roosevelt's administration. Steel was eventually named as the second Commissioner of Parks at Crater Lake National Park in 1920.

Steel had extensive experience in the postal service, working as a letter carrier for years in Portland before being appointed as Superintendent. He was also a real estate and insurance entrepreneur in Portland, co-owning Wilbur and Steel in the early 1890s. Mountaineering was another great passion of Steel's, and he is credited with founding the still-extant Mazamas mountaineering organization at the summit of Mt. Hood in 1894.

Steel married Lydia Hatch, a postal clerk, on February 16, 1900. He died in Medford, Oregon, on October 21, 1934.