The salmon that come through the locks in Ballard come in three waves according to the park rangers.  There are three types of salmon and each type comes at a slightly different time of year.  (I’m sure the sales like this so they get three feeding times!). Within the fish ladder, they have a viewing gallery which allows you to see the fish as they loiter for a while before surging up the next step in the ladder against the flowing water.

It is quite impressive to see how fast they can go when they make an effort.  They swim gently against the current in the viewing area waiting for a time that seems appropriate to them.  Then they align themselves with the inlet port through which the water is rushing.  This needs a dose of acceleration to avoid being pushed back into the gallery and then, once they are stabilized, a surge of effort and they zip up the port.  Photos don’t do it much justice but video is a better medium.  The reflections off the glass are not ideal but you will get the idea.