Off-channel features such as alcoves and side channels can have important ecological functions for large rivers such as the Willamette River. Some species and age classes of fish may select these features instead of the main channel to feed, avoid predation by other fish, escape fast water, or seek out cool water in the summer. Other organisms such as amphibians, mussels, and birds may also be attracted to alcoves and side channels because of unique physical and water quality characteristics. This proposal describes research to evaluate the functions of alcoves and side channels in a large river ecosystem, determine factors that currently affect their ecological functions, and identify future management actions that could be taken to improve these functions. In addition, the authors intend to relate the processes occurring within alcoves and side channels to processes occurring in the main channel, in adjacent ground water, and the riparian vegetative community.