I’m not sure if this has been posted before, but the US Fish and Wildlife Service does aerial surveys of pools 4-14 of the Mississippi River each fall to track the annual migration. It also breaks the river into smaller “districts” such as the La Crosse district (pools 7-8) to allow you to focus on your home area a bit more. The current data is from 2008 but they should be posting updates for 2009 soon. Hope it’s helpful…
jeff_hansen
Posts: 475