Spellman B1-27-5475 is a privately owned earth dam located in Campbell, Wyoming, specifically on County Road 75, spanning the Tank Draw river or stream. Built in 2008 for irrigation purposes, this dam stands at a height of 40 feet with a hydraulic height of 35 feet and a structural height of 40 feet. With a storage capacity of 49 acre-feet and a normal storage of 33 acre-feet, this dam covers a surface area of 3.19 acres and has a drainage area of 0.13 square miles.

Despite being classified with a low hazard potential and fair condition assessment, Spellman B1-27-5475 is subject to regular inspections, with the last one conducted in May 2021. The dam features an uncontrolled spillway, with a spillway width of 53 feet and an outlet consisting of one valve. Although the risk assessment is moderate, this dam has not yet had an Emergency Action Plan prepared or updated. With Liz Cheney representing Congressional District 00, Wyoming, and the Omaha District overseeing the USACE operations, Spellman B1-27-5475 remains an essential structure for water resource management in the region.