Bast No. 1 Stock is a privately owned dam located in Niobrara, Wyoming, near the city of Edgemont SD. Built in 1968, this earth dam serves multiple purposes including fire protection, stock watering, and small fish pond habitat. With a structural height of 29 feet and a length of 505 feet, the dam holds a maximum storage capacity of 49 acre-feet and covers a surface area of 4 acres.

Managed by the Wyoming State Engineer's Office, Bast No. 1 Stock is classified as a low hazard potential structure with a fair condition assessment as of the last inspection in July 2020. The dam has a moderate risk assessment rating, indicating a moderate level of risk associated with its operation and potential impact in the event of failure. Despite being uncontrolled, the dam features a spillway width of 310 feet to safely release excess water during periods of high flow.

Though the dam has not been significantly modified over the years and has no associated structures, it plays a crucial role in water resource management in the region. Enthusiasts of water resources and climate monitoring will find Bast No. 1 Stock an interesting case study in dam engineering and maintenance practices.