Important Bird Area.
Sweet Marsh, south entrance, Segments A & B (Martin's Lake), and refuge In northeast Bremer Co. Enter Tripoli from U.S. 61 going east along Hwy. 92. Where 92 turns north in town, continue east for two miles along C-28/170th St. to the marsh's south entrance, on the north side of the road. The first parking area to the right leads to Segment A and its dike, on the east. The farther parking area leads to the refuge, which is the first water on the left; and to Segment B, farther ahead on the right side of the dike. Also see map at: http://www.jccniowa.org/~icbc/sweetmarshpg.html

This area has many different habitat types and is an important gathering and resting area for many species of shorebirds and waterfowl. It is also a stopover area for many species of passerines (including warblers and sparrows). Over 270 species of birds have been seen in or near the area.

From Waterloo take U.S. Highway 63 North to State Highway 93 and take this highway to Tripoli. Continue across County Road V43 at the stop sign in Tripoli. Follow this paved road about 2 or 3 miles to the south entrance to the area (just past the second bridge). Turn left into the park. There are several more entrances (two on the east side, one on the north and two on the west) to the area as you drive around the marsh on gravel roads.