Griswold No. 1 is a privately-owned earth dam located in Niobrara, Wyoming, along the Griswold Draw river. Built in 1954, the dam serves multiple purposes including fire protection, stock watering, and small fish pond maintenance. With a height of 25 feet and a storage capacity of 133 acre-feet, Griswold No. 1 covers a surface area of 9.9 acres and has a spillway width of 100 feet. Although it has a low hazard potential, the dam is regularly inspected and its condition is assessed as fair.

Managed by the Wyoming State Engineer's Office, Griswold No. 1 is subject to state regulations and inspections to ensure its safe operation. The dam has a moderate risk level, with a risk assessment rating of 3. While it currently meets guidelines for emergency action plans, there is no available information on the last revision date or the existence of inundation maps. The dam is situated in Congressional District 00 of Wyoming, represented by Liz Cheney (R), and falls under the jurisdiction of the Omaha District of the US Army Corps of Engineers.

Water resource and climate enthusiasts interested in Griswold No. 1 will find it to be a significant infrastructure for local water management and conservation efforts. Despite its low hazard potential, the dam plays a crucial role in providing essential services such as fire protection and stock watering in the region. With ongoing inspections and maintenance, Griswold No. 1 continues to contribute to the sustainable use of water resources while complying with state regulations and safety standards.