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This detailed topographic map of Yosemite Valley in Yosemite National Park, California, is a product of the U.S. Geological Survey's early 20th century mapping efforts. Originally surveyed in 1905-1906, the map underwent partial revisions in 1934 and 1946, with relief shading added in 1946. This historical layering reflects the evolving understanding and representation of this iconic landscape over time.

The map vividly depicts the dramatic topography of Yosemite Valley, showcasing its characteristic sheer granite cliffs, domes, and waterfalls. Employing a polyconic projection and referencing the North American datum, the map uses shaded relief and contour lines at 50-foot intervals to represent the terrain with remarkable precision. The valley floor is rendered in green, with the sinuous path of the Merced River traced in blue through its heart.

Key features such as El Capitan, Half Dome, and Yosemite Falls are clearly labeled, offering both geographical and cultural reference points. The map's scientific accuracy is evident in its creation process: F.E. Matthes conducted the topographic survey, while C.F. Urquhart performed the triangulation, ensuring a high degree of cartographic reliability.

At a scale of 1:24,000 (where 1 inch represents 2000 feet), the map provides an expansive yet detailed view of the valley. It goes beyond mere topography to include roads, trails, and structures, offering a comprehensive picture of both natural and human elements in the landscape.

Supplementary information enhances the map's utility and context. An index map situates Yosemite Valley within California, while a table of elevations for principal points provides crucial data for understanding the valley's vertical dimensions. The inclusion of this metadata speaks to the map's function as both a scientific document and a tool for public understanding of this natural wonder.

Provenance

Colonel George Ruhlen (1884-1971), noted Southern California historical geographer.

The map has a few Ruhlen manuscript additions, including notes about the New and Old Roads into the park, and a note for the "Fort Monroe old entrance Check Point".