With this final rule, the National Oceanic and Atmospheric Administration (NOAA) expands the boundary of Thunder Bay National Marine Sanctuary (TBNMS or sanctuary), clarifies the correlation between TBNMS regulations and Indian tribal fishing activities, and revises the corresponding sanctuary terms of designation. The new boundary for TBNMS increases the size of the sanctuary from 448 square miles to 4,300 square miles and extends protection to 47 additional known historic shipwrecks of national significance. NOAA has prepared a final environmental impact statement for this action.