1969 Map of Big Lost River Sinks

About this map

The National Reactor Testing Station dominates this landscape in Butte County, marking a period of intense federal investment in Idaho's desert. The terrain is characterized by the complex hydrology of the Big Lost River, which terminates in the Big Lost River Sinks, a series of depressions where surface water vanishes into the aquifer. A prominent Dry Channel and numerous depressions reflect the ephemeral nature of water in this high-altitude basin. Along the western edge, the foothills of the Lemhi Range rise sharply from the valley floor, providing a stark contrast to the flat, sandy expanses of Sand Dunes found further east. Transportation across this secure government facility is limited to thoroughfares like Lincoln Boulevard and several rugged routes marked as Jeep Trail, while several Borrow Pits indicate localized excavation for infrastructure development within the testing station boundaries.