Miller Dam, also known as West Branch Dam, is a private-owned structure located in Mitchell, Oregon. Completed in 1990, this earth-type dam stands at a height of 31.5 feet and serves primarily for irrigation purposes, holding a storage capacity of 19 acre-feet. Situated on Bridge Creek and West & Spring Branch, the dam plays a crucial role in managing water resources in the area, with a drainage area of 0.79 square miles and a maximum discharge capacity of 120 cubic feet per second.

Despite its low hazard potential, Miller Dam is regulated by the Oregon Water Resources Department and undergoes regular inspections, with the last one conducted in September 2014. The dam features a slide gate as its outlet control mechanism and is equipped to handle emergency situations. While its condition assessment is currently not rated, the dam's structure and operational mechanisms are vital for water management in Wheeler County. With its strategic location and capacity to support irrigation needs, Miller Dam is an essential component in sustaining water resources in the region and ensuring efficient water distribution for agricultural purposes.