Lemhi River Restoration Monitoring & Evaluation

Mount Hood Environmental will continue long-term monitoring and expand the short-term monitoring initiated in 2023. The objective is to assess the impacts of restoration and rehabilitation efforts on Chinook salmon by maintaining critical PIT tag infrastructure and continuing comprehensive sampling efforts throughout the Lemhi River. Specifically, this proposal will help support efforts to:

* Conduct annual Chinook salmon redd surveys

* Maintain 5 core IPTDS and up to 13 corded PIT tag antennas

* Perform summer and fall electrofishing surveys

* Support data cleaning and analyses needed to address site- and population-level research questions within the Lemhi River, alongside general fish-in and fish-out monitoring



Data from these initiatives will provide insights on:



* How juvenile Chinook salmon life history strategies influence growth, outmigration timing, and survival to the hydrosystem (Lower Granite Dam).

* The effects of restored habitat occupancy-both in timing and residency duration-on ju-venile Chinook salmon growth, outmigration timing, and survival to the lower Lemhi River and the hydrosystem.



These efforts will quantify the benefits of restoration activities at both the project and population levels within the Lemhi River, providing valuable insights and information applicable to other watersheds across the Pacific Northwest.

The Lemhi River offers a unique opportunity to utilize extensive in-stream fish detection infrastructure to address critical questions about population- and project-level responses to restoration efforts. Our proposed data collection and research on how restoration projects

influence fish growth, survival, outmigration timing, and population-level dynamics will not only guide future restoration and monitoring in the Lemhi River but also has broad applicability to other watersheds in Idaho and the Pacific Northwest.