As a student at the University of Wisconsin, John Muir often visited with Dr. Ezra Carr and his family, and the impressionable young man came to regard Mrs. Carr as his spiritual mother. A keen botanist, she shared Muir's passion for nature, and the two formed a lasting bond. After heading west to explore the wonders of Yosemite, the future founder of the Sierra Club and wilderness preservationist wrote many heartfelt letters to Mrs. Carr. In his letters, Muir extolled the region's wonders and proclaimed the joys of his daily discoveries amid the vast forests and towering mountains. These letters, first published in 1915, offer fascinating insights into Muir's daily life in Yosemite. In lyric terms, he recounts his days of sheepherding and guiding visitors through rugged landscapes. With reverence, he describes the region's diverse splendors and his studies of wildlife, trees, and flowers. The letters provide a moving portrait of a friendship based on a mutual love of nature and God, reflecting a devotion to the natural world rarely seen in modern life.