Enl. Gerry Nicolaysen No. 1 is a privately owned earth dam located in the Big Muddy Oil Field in Converse, Wyoming. Built-in 1966 for irrigation purposes, this dam stands at a height of 35 feet with a hydraulic height of 30 feet and a length of 1350 feet. It has a storage capacity of 1163 acre-feet and covers a surface area of 74.1 acres. The dam's spillway is uncontrolled with a width of 31 feet, and it is equipped with one valve outlet gate.

Despite being categorized as having a low hazard potential and fair condition assessment, Enl. Gerry Nicolaysen No. 1 is subject to regular inspections and maintenance. The last inspection was conducted in August 2018, with an inspection frequency of every 5 years. The dam is considered to have a moderate risk level (3), and while it meets regulatory guidelines, there is room for improvement in terms of emergency preparedness and risk management measures. With its vital role in irrigation and water supply, continued monitoring and maintenance are crucial to ensure the safety and efficiency of this important water resource infrastructure in Wyoming.