The Kelt Reconditioning and Reproductive Success Evaluation Project is a research, monitoring, and evaluation (RM&E) uncertainties category project, that was funded through the 2008 Columbia Basin Fish Accords. The objectives are to evaluate methodologies to produce viable artificially reconditioned repeat steelhead (Oncorhynchus mykiss) spawners and evaluate reproductive success, physiology, homing, and geographic differences. The project was recently reviewed (ISRP 2021-08) by the Independent Science Review Panel (ISRP). Our annual report contains many sections of the review document we submitted to the ISRP to provide a wider distribution of the comprehensive results. Our work occurs in both the Yakima and Snake river-basins, additionally we make some contrasts and comparisons with the Kelt Reconditioning Project in the Upper Columbia River (Project 2008-458-00). We focused on collecting steelhead kelts at juvenile bypass facilities at Prosser, Lower Granite, and Little Goose dams. These kelts were reconditioned (given prophylactic treatments and fed a specially formulated diet) at Prosser and Dworshak National Fish (DNFH) hatcheries. Survival of long-term reconditioned kelts has been 44% (22 years) at Prosser Hatchery and 37% (11 years; 44% over the last 9 years) for mixed stock collections reconditioned at both Nez Perce Tribal and Dworshak National Fish hatcheries combined. In total, we released 525 and 4,989 reconditioned kelt steelhead in the Snake and Yakima rivers since 2011 and 2000, respectively. In 2021, unmarked upstream “wild” migrant adult steelhead return counts to Bonneville Dam was the worst year since unclipped fish were recorded beginning in 1994, this places great importance on safety net programs such as the kelt reconditioning program. Years with low runs typically translate into lower abundance of kelts but the value of each fish increases. In 2021, we collected 530 kelts in the Snake River. From this collection of 530, 264 were PIT tagged and released back to the river, 196 were taken to DNFH for reconditioning. There were 65 reconditioned-mature (a combination of consecutive and skip spawners) fish that were released into the Snake River below Lower Granite Dam on November 10, 2021. In 2021, we collected 365 kelts in the Yakima River. From this collection of 365, 5 were PIT tagged and released back to the river, 360 were taken to Prosser Hatchery for reconditioning, and 268 reconditioned-mature consecutive spawners were released in the Yakima River below Prosser Dam on October 28, 2021. Additionally, 53 reconditioned-immature kelts were trucked and released below Bonneville Dam on October 21, 2021. Reproductive success of reconditioned steelhead was confirmed in the Yakima River tributaries of Satus and Toppenish creeks, with genetic parentage assignments (2,700 samples from Satus and 3,087 samples from Toppenish collected from 2013 through 2019). Lifetime reproductive success for female reconditioned kelt steelhead in the Yakima River is estimated as 2.49 relative to steelhead that successfully spawn once. Studies applying tools from fish physiology and endocrinology to issues in kelt reconditioning were continued in 2021. These studies aim to achieve a sufficiently detailed understanding of the physiology of reconditioning in kelt steelhead to provide a scientific basis for maximizing the success of reconditioning programs. Screening of kelts for maturation status using plasma estradiol levels has become an essential part of the project. In 2021, we sampled blood at DNFH and Prosser hatcheries, and provided maturation status of individual fish at DNFH and Winthrop to project managers so that consecutive and skip spawners could be managed appropriately. The 2021 results were added to a comparison of the performance of the three Columbia River Basin kelt projects in terms of survival and maturation rates. In addition, we are continuing data analysis in a study where we are combining the results of a genetic analysis enabling classification of Yakima River kelts by subpopulation, with survival, physiological, and migration data. From 2008 to 2021, we have detected conclusive evidence of 146 kelts showing repeat homing and upstream movement patterns and an additional 1,414 kelts that is consistent with repeat homing in the Yakima basin. Progress continues to be made toward the realization of a dedicated kelt reconditioning facility for the Snake River in 2021. Efforts included: Review Team review of 10%, 60%, and 90% facility design documents created by R2 Resource Consultants, Inc. Development of monitoring and evaluation budget is ongoing. As the kelt program moves towards a production program we have identified some additional areas that this project can move forward on towards 3 important goals the ISRP has identified: 1. Focus on identifying and collection of at-risk populations, 2. Transferring kelt collection and rearing techniques through documentation, 3. Development of plan to provide this information to agencies that could utilize technology for at risk populations. Lessons learned and adaptive management list has continued to grow, which will provide a good outline for development of our documentation for kelt reconditioning technologies and techniques to share with agencies and groups that have interest in development of kelt reconditioning programs. Due to the ongoing COVID-19 restrictions, shutdowns of many conferences and travel have resulted in diminished opportunities for presentations, a comprehensive list of 2021 presentations are available in the appendices along with peer-reviewed articles regarding steelhead kelts produced by CRITFC and its partners along with novel additional sources.