Hanna is a concrete dam located in Carbon, Wyoming, along the Rattlesnake Creek, with a primary purpose of water supply. Built in 1934 by designer Ellis Hudman, this dam stands at a height of 25 feet and has a hydraulic height of 21 feet, providing a normal storage capacity of 62 acre-feet. With a fair condition assessment as of July 2017, Hanna has a low hazard potential but a high risk assessment rating of 2, indicating the need for ongoing monitoring and management.

Owned by the local government, Hanna is regulated by the Wyoming State Engineer's Office, with state permitting, inspection, and enforcement in place. The dam features a spillway width of 12 feet and three valve outlet gates for operational control. While no associated structures exist, Hanna serves as a crucial water resource infrastructure for the surrounding area. With a risk management plan in place, Hanna continues to play a vital role in water management and supply within the region.

Despite its age, Hanna remains a key structure in the water resource management system, demonstrating the importance of maintaining and monitoring aging infrastructure for climate resilience. With its location in a scenic area of Wyoming, Hanna stands as a testament to the engineering feats of the past and the ongoing efforts to ensure the safety and reliability of water resources in the face of changing climate conditions.