The two divisions of the Port Louisa NWR are important to Iowa birds because of the habitat. Species such as Bald Eagles, Red-Shouldered Hawks, Barn Owl and King Rail have either nested or attempted to nest there, according to their website. Three or more species in the high conservation priority category have also been identified as nesting species. Some include the Prothonotary and Cerulean Warbler and American and Least Bittern. The habitat that is there is unique because it is maintained and supports this assemblege of birds. Each year large groups of waterfowl, shorebirds and songbirds can be found here during migration. This area is important for research, including future research opportunities.

The Big Timber Division is located two miles south of Muscatine, Iowa in Pool 17. It is 1,758 acres of land which is mostly islands. Islands included are Turkey, Turkey Towhead, Ramsey and Otter Islands. The Louisa Division is located just east of Wapello, Iowa. Directions to the refuge headquarters are from Wapello, IA. Enter Wapello from highway 61. From Wapello, IA turn onto highway 99 (turn is marked). Just outside of town turn left onto 1st Avenue (turn is marked). Follow the main road (County Hwy 62) to its end on X61. At X61 turn left and watch for the refuge headquarters on the right.