1948 Map of Sinker Butte

About this map

The Boise Emigrant Trail follows the canyon rim above the Snake River in this post-war landscape of the high Idaho desert. This map documents a rugged river corridor where history and infrastructure meet, specifically at the Otter Massacre Site and the nearby Jacob Reuben Graves located on the bench above Sinker Creek. These markers reflect the challenges of 19th-century westward migration along the trail. By the late 1940s, the area had transitioned into a land of ranching and early utility development, shown by the Gabica Ranch and Montini Ranch alongside the Swan Falls Power Plant at the river's edge. The terrain is dominated by prominent volcanic features like Sinker Butte and Sinker Creek Butte, providing a stark backdrop to the numerous wells and springs scattered across the plateau for livestock.