Wiki's pic of what it calls the inlet bridge is what whoever wrote this is calling the outlet bridge......

8. Indicator Tree / Outlet Bridge

This tree, called the indicator tree, is growing very close to, even within, the large holly tree. Look for the numbered post to help guide you to the correct tree. This tree is called the indicator tree because it blooms about a week earlier than most of the cherry trees;thus, it is an indicator that the peak blooming period is soon to occur. Since the park has been administrated by a variety of organizations throughout the years, it remains a mystery as to who planted the tree, when it was planted, and even what species of cherry tree it is.

To the north, the path and road cross over the Outlet Bridge. This is where the Tidal Basin empties into the Washington Channel. See stop # 5 for more information about the Tidal Basin.