The article explores the evolving portrait of nature in American literature in the first half the 20th century, a period marked by significant advancements in the field of science, economy, warcraft, transportation and oil and gas industry. The analysis identifies numerous representations of nature based on comprehensive review of literary works and theoretical ideologies including Romanticism, Naturalism, and Ecocriticism. The study identifies valid points by examining authors such as John Muir, Robinson Jeffers, Jack London, John Steinbeck and their conceptualization of nature in the middle of societal changes and two World wars. The findings reveal a shift from idealized, spiritual views of nature to emphasized depictions of environmental degradation, vulnerability of human spirituality, and ecological crises. Highly influenced by Darwinʼs theories and technological advancements, writers illustrated nature as both a force of sustenance and destruction, alongside pessimistic views of the working-class peopleʼs day-to-day life. The research underscores the role of the nature portrayal in understanding ecological and psychological dimensions of early 20th century America, highlighting the literatureʼs role in fostering ecological awareness and ethical responsibility.