1959 Map of Frank Island

About this map

Yellowstone Lake dominates this 1950s survey of the wilderness interior, centering on the remote islands and southern arms of the nation's first national park. The map records the complex shoreline from West Thumb to the Southeast Arm, documenting backcountry infrastructure like the Park Pt Patrol Cabin and Heart Lake Patrol Cabin. The Continental Divide winds through the southern terrain, separating the drainage of Surprise Creek and Heart Lake from the main lake basin. This geography illustrates the park’s rugged connectivity before modern expansion, with various routes like the Loop Road, Thorofare Trail, and several pack trails serving as the primary arteries for rangers and early visitors. Landmarks such as Frank Island, Dot Island, and The Promontory provide essential navigational reference points for this high-altitude aquatic landscape.