MADISON (WKOW) -- Cities along rivers in Wisconsin are planning annual bald eagle parties.
Large portions of area rivers are frozen. That means the eagles tend to group together and fly over areas of open water, making them much easier to see.
The Department of Natural Resources says Wisconsin's groupings are the largest concentration of wintering bald eagles in the lower 48 states.
Sauk City and Prairie du Sac on the Wisconsin River will hold their 23rd Annual Bald Eagle Watching Days January 15 & 16.
On the Mississippi, Cassville will hold its 17th Annual Bald Eagle Days January 30 & 31.
There are 1,145 pairs of eagles in Wisconsin.