Sides No. 1 is a private irrigation dam located in Niobrara, Wyoming, along the Sides Draw river. Built in 1952, this Earth-type dam stands at 30 feet high and spans 503 feet in length, with a storage capacity of 234 acre-feet. The dam serves the primary purpose of irrigation, providing water for agricultural activities in the region.

Despite being regulated by the Wyoming State Engineer's Office and regularly inspected, Sides No. 1 has a low hazard potential and is assessed to be in fair condition as of August 2020. With a moderate risk level of 3, the dam has an uncontrolled spillway with a width of 50 feet. While the dam has not been modified in recent years, it features one slide gate for outlet control.

Water resource and climate enthusiasts interested in the infrastructure and management of irrigation dams will find Sides No. 1 a fascinating example of a privately-owned structure designed to support agriculture in the region. Its historical significance, design features, and risk assessment provide valuable insights into the challenges and opportunities associated with water resource management in Wyoming.