Pexton No. 1, located in Guernsey, Wyoming, is a privately-owned earth dam completed in 1963 for irrigation purposes along Reid Creek. With a height of 38 feet and a storage capacity of 177 acre-feet, the dam serves multiple functions including fire protection, stock water supply, and small fish pond maintenance. The dam's spillway, with a width of 50 feet, is uncontrolled and can handle a maximum discharge of 804 cubic feet per second.

Despite being classified as having a low hazard potential, Pexton No. 1 is rated in fair condition as of the last inspection in September 2021. The dam's risk assessment is moderate (3) and it undergoes inspections every 5 years to ensure its structural integrity. The surrounding area of Converse County benefits from the dam's water storage capacity and its contribution to local agriculture and wildlife. Water resource and climate enthusiasts would find Pexton No. 1 a fascinating example of water management infrastructure in the region.