Galloping Jack is a privately owned earth dam located in Johnson, Wyoming, with a primary purpose of irrigation. Constructed in 2006, this dam stands at a height of 37 feet and has a hydraulic height of 32 feet. With a storage capacity of 90 acre-feet, it serves multiple purposes including fire protection, stock watering, and small fish pond maintenance.

The dam spans 836 feet in length and covers a surface area of 4.8 acres, with a drainage area of 0.05 square miles. The maximum discharge capacity of Galloping Jack is 497 cubic feet per second, with an uncontrolled spillway width of 30 feet. Despite being classified as having low hazard potential, the dam is regularly inspected and maintained, with its condition assessed as fair during the last inspection in July 2019.

Galloping Jack plays a vital role in supporting the local agricultural community by providing irrigation water and additional benefits such as fire protection and recreational opportunities. Its location near Trotting Hare Draw highlights its importance in water resource management in the region. As a key infrastructure for water storage and distribution, Galloping Jack contributes to the sustainable utilization of water resources in Wyoming.