Belknap Creek No. 1 is a historic earth dam located in Cody, Wyoming, completed in 1917 for the primary purpose of irrigation. This offstream structure stands at a height of 20 feet and has a hydraulic height of 15 feet, storing up to 151 acre-feet of water for agricultural use. Despite its age, the dam has a low hazard potential but has been assessed as being in poor condition as of June 2020.

Owned privately, this dam is regulated by the State Engineer's Office of Wyoming, with inspection, enforcement, and permitting responsibilities falling under the state's jurisdiction. With a drainage area of zero and a small surface area of 9 acres, Belknap Creek No. 1 plays a crucial role in water supply for the surrounding area. Although the dam's condition is less than ideal, its historical significance and importance for irrigation make it a noteworthy structure for water resource and climate enthusiasts to monitor and potentially support in maintenance and rehabilitation efforts to ensure its continued functionality and safety.