Upper Midway, located in Langell Valley, Oregon, is a federal-owned irrigation dam on the TRIB Lost River. Built in 1959 by the Bureau of Land Management, this gravity dam stands at a hydraulic height of 9 feet and a structural height of 13 feet, with a length of 1095 feet. The dam has a storage capacity of 423 acre-feet, with a normal storage level of 286 acre-feet, serving the primary purpose of irrigation in the region.

Managed by the Bureau of Land Management, Upper Midway has a low hazard potential and has not been rated for its condition assessment. The dam features a slide (sluice gate) outlet gate and is inspected every 5 years, with the last inspection conducted in September 2017. Despite its age, the dam has not undergone any modifications in recent years, and there are no emergency action plans in place at this time. While the risk assessment and management measures are not specified, the dam continues to provide vital irrigation water for the surrounding area within Klamath County, Oregon, under the oversight of federal agencies.