The St. Croix River and adjacent riparian and upland habitats contains a diverse assemblage of birds that depend on this area. It is a natural north-south migratory corridor. Two Great blue heron colonies in the area had a combined total of 534 nests in 2004. Eleven pairs of Bald eagles were counted nesting along this stretch of the St. Croix during that same time. This is one of the best concentrations of breeding Red-shouldered hawks in the state. Pairs of Louisiana waterthrush can be found in nearly every stream valley dissecting the river bluffs. Prothonotary warblers are common on the St. Croix and reach their northern limit in Minnesota here.