2021 Map of Elk Basin SW

About this map

Ralston Flats anchors the southern portion of this landscape, where the human footprint is most visible through an intricate network of irrigation engineering. This dry basin environment is defined by the management of water, evidenced by the Middle Sand Coulee Reservoir and Upper Sand Coulee Reservoir. The terrain is shaped by significant geological features like the elevated Polecat Bench and the carved depths of Big Sand Coulee. The irrigation infrastructure, including the Alkali Cr Ditch and the Ralston Lateral, suggests a transition from the wilder coulees to managed agricultural or ranching lands. These waterways, alongside smaller channels like Lateral H-1.43, provide a detailed look at how this part of Park County has been modified to support settlement in a high-plains climate.