Last Chance Ranch – Upper Pahsimeroi Phase Restoration

The Idaho Department of Fish and Game implemented habitat treatments on 0.87 miles of the Pahsimeroi River near the town of May, ID. The Last Chance Ranch - Upper Pahsimeroi Phase Restoration is part of a multi-phase habitat restoration effort on the Last Chance Ranch property that will increase and enhance summer and winter foraging and rearing habitat for ESA listed juvenile salmonids. Phase 2 of this project, on the Pahsimeroi River in the downstream reach is planned for construction in 2025 under PCSRF project 013 23 SA. Last chance Ranch is under a conservation easement and cattle grazing is excluded from the riparian zone.

The project goal was to increase habitat capacity for juvenile salmon and steelhead. IDFG and the Bureau of Reclamation developed designs, incorporating an aggressive approach to fish habitat and floodplain connectivity. Project actions implemented to meet these objectives included: 1) installing several types of large and small woody debris to improve instream habitat and channel complexity, 2) utilizing both large wood and engineered riffles to raise grade and force a proportion of the flow into side channels and on the floodplain. 3) utilizing existing disconnected and excavated side channels to increase overall channel length, and lateral habitat connectivity, and 4) enhancing native riparian vegetation by planting and seeding native species to provide long-term habitat and water temperature benefits to fish and other native species.

Note that engineered riffles, Beaver Dam Analogs, islands, and habitat benches are captured under other engineered structures in the metrics.

Rehabilitation of the upper Pahsimeroi River on Last Chance Ranch is part of a multi-project effort to improve floodplain and riverine processes and functions on the mainstem Pahsimeroi River as well as several tributary spring channels on this property. This will directly increase habitat capacity for juvenile salmonids. Under the proposed project, current conditions will be improved by restoring instream channel habitat using woody habitat structures and engineered riffles to improve lateral connectivity to the floodplain and side channels. This will result in improved survival for all freshwater life stages. The project will provide increased foraging and rearing (summer and winter) opportunities for juvenile Chinook salmon and steelhead.