Little Thompson, also known as Hillsboro, is a private earth dam located in Weld County, Colorado, specifically in the city of Milliken. Completed in 1896, this irrigation dam stands at 29 feet tall and stretches 1000 feet in length, with a storage capacity of 767 acre-feet. It is regulated by the Colorado Department of Water Resources and undergoes regular inspections to ensure its structural integrity.

The dam's primary purpose is irrigation, serving the local community by providing water for agricultural use. It is situated on the Little Thompson River-OS and is managed by private owners. Despite its significant hazard potential, the dam is currently in satisfactory condition and meets regulatory guidelines. With a moderate risk assessment rating, the dam is equipped with an uncontrolled spillway and has a maximum discharge capacity of 618 cubic feet per second.

Water resource and climate enthusiasts will find Little Thompson to be a historic and essential infrastructure in Colorado's water management system. Its presence contributes to the region's agricultural sustainability and highlights the importance of proper dam maintenance and regulation in the face of changing climate conditions. As a key player in local water resource management, Little Thompson stands as a testament to the ongoing efforts to balance water usage, safety, and environmental stewardship in the region.