|The John Muir Memorial Shelter is eligible for the National Register at the national level of significance under Criterion A in the area of Conservation and under Criterion C in the area of Architecture. The only building conceived and erected by the Sierra Club to honor its first President and co-founder, John Muir, the shelter is located at the proximate mid-point of the John Muir Trail (JMT) section of the Pacific Crest Trail (PCT). The trail was established through the Club's lobbying efforts in 1915, a year after Muir's death, and thus it was named in his honor. Muir is regarded by modern environmental historians as the most influential American conservationist in the nation's history -and the father - of the National Park Service. The Muir Memorial Shelter is significant under Criterion A: Conservation as the sole commemorative structure in the United States erected to pay tribute to the pioneering role played by Muir and the Sierra Club in the American conservation movement and the stewardship of natural resources. The shelter is further significant under Criterion C: Architecture for its distinctive Italian-derived Trullo Hut design and its indigenous rustic stone construction. It is one of two mountain shelters erected in the United States in the Italian Trullo Hut design tradition, and the only one to provide the communal features of a centralized hearth, decorative fireplace mantel and perimeter seating for thirty. Its native granite fieldstone materials are in visual harmony with its high Alpine environment, thus meeting the principles set forth by the NPS landscape division in the late 1920s to reflect the practices of Park Rustic architecture. The shelter was designed by Henry Gutterson who was among the San Francisco Bay Area architects to develop a distinctive style based upon Arts & Crafts design that was extremely influential in the development of park architecture. Significant as well for its recreational association with national parks and its architectural value as a strategically sited mountain shelter, independent of its association with John Muir, the property also meets Criteria Consideration F. The shelter's period of significance period of significance is from 1930 to 1966, beginning with its design and construction in 1930 and extending to its fiftyyear- old historic threshold of 1966. which recognizes the continuous commemortative function and significance of the resource.