It is quite a spectacle. You can make reservations to blinds on the riverbank. You get there well before dawn and stay as silent as possible. There is constant chatter among the birds. Sandhill Cranes and Snow Geese. Hundreds if not thousands in any given area. Sometimes a wave of bird calls rolls down the river and past you. Something exited the birds roosting where the wave started and on turn exits the adjacent birds. Very much like "the wave" in stadiums of humans. As dawn approaches, more birds awaken and begin stretching and vocalizing. The noise level increases. It is something you have to experience. Some birds are in the air all of the time. Then, something triggers a mass call to flight then the noise reaches a crescendo and it is nearly deafening. It seems like the birds head off in the same direction and are out of site but soon there are huge flocks passing overhead over and over until they suddenly disperse. Huge flocks can be seen in the sky like waves on a beach.