The recovery plan for Snake River Sockeye Salmon includes annual releases of up to 1 million hatchery-reared smolts. A new purpose-built hatchery was constructed (near Springfield, Idaho) and began releasing smolts to Redfish Lake Creek (near Stanley, Idaho) in 2015. Various complications associated with fish transport contributed to reduced survival, but post-release success of Springfield Hatchery-reared smolts remained uncharacteristically low following optimization of fish transport protocols. Evaluation of smolts released in 2017 suggested that differences in water chemistry between the hatchery and release site may have contributed to morbidity and mortality observed after release. Follow-up experiments with pre-smolts confirmed that direct transition from hard, high-alkalinity water at Springfield Hatchery to soft, low-alkalinity water at Redfish Lake Creek caused a significant physiological stress response. Coping with a dramatic shift in water chemistry is difficult under any circumstances; coupled with the other challenges facing hatchery-reared smolts at release, it may be physiologically unmanageable. A variety of modified release strategies have been evaluated, including acclimation to water with an intermediate chemistry profile, water mixing at release, and in-transit water softening. Results of ongoing experimentation will be discussed, along with implications for future rearing and release strategies for Snake River Sockeye Salmon smolts.