The planning and designing of steep channels suitable for fish passage has become increasingly common as an alternative to structural fish ladders at dams. They are found at dam removal sites, naturalistic bypass channels that allow fish to swim around and past dams, and at created fill ramps that allow fish to swim over dams. Each of these three steep channel types have unique features such as entry and exit needs; partial or full river flow design criteria; and rigid, threshold, or mobile beds. All three types of steep fish passable channels have a common feature in the main channel segment. To be fish passable, the depth of flow, velocity, and cover must be scaled to the swimming and biological characteristics of one or more fish species or assemblages. Steep channels have the potential for high velocity and high turbulence flow, plus supercritical conditions that are difficult to analyze. A design protocol is presented, drawing upon classic hydraulics; use of analog reference reaches with similar slopes; and geomorphic relationships between slope, discharge, and profile type. Steep mobile bed channel types are also discussed with basic techniques to analyze sediment continuity. Numerous examples of constructed steep fish passable channels are used to illustrate the discussion.