ten years he spent in the "blackjacks" of his homeland, observing nature and reflecting on the influence of the environment on Osage culture. He wrote much of this in the stone cabin that he built in the Osage Hills in 1929. This area is now preserved as part of the Tallgrass Prairie Preserve. The book is a combination of autobiography, philosophical treatise, and observations by an amateur naturalist. Some critics compared it to Henry David Thoreau's Walden. Lee Schweninger noted that Mathews used irony to create distance between the narrator and himself as the subject of autobiographical reflection. He also wrote about himself as a settler, and critiqued European-American culture, while committing actions similar to those of other settlers who disrupted the natural balance. Mathews's Life and Death of an Oilman: The Career of E. W. Marland (1951) was his only biography; it explores the life of a multi-millionaire Oklahoma oilman and politician, who also served as governor of the state in the 1930s. He created a social scandal by marrying his much younger adoptive daughter, Lydie Marland. Based on years of collecting information from tribal elders through the oral tradition, in addition to conducting historical research, Mathews wrote The Osages: Children of the Middle Waters (1961). It has been described as "his magnum opus and a pioneering achievement for both its reliance on the oral tradition and presentation of a particular tribal history from an Indian point of view." His book was the product of his working with tribal elders to preserve and interpret their common culture. Two books of Mathews have been published posthumously, in efforts to bring his work to a wider audience. Another autobiography, Twenty Thousand Mornings was published in 2012, edited by Susan Kalter. In the 1960s Mathews wrote a number of short stories, some drawing from folk traditions of the Osage and other cultures, including Scotland. Selected stories from these unpublished manuscripts were published in 2015 as Old Three Toes and Other Tales of Survival and Extinction. Mathews told these stories from the point of view of bird and animal protagonists, an act of imagination that decenters human life. Works Wah'kon-tah: The Osage and The White Man's Road (1929) Sundown (1934) Talking to the Moon (1945) Life and Death of an Oilman: The Career of E. W. Marland (1951) The Osages: Children of the Middle Waters (1961) The following were published posthumously: Twenty Thousand