Knox-Marsellus and Puddler Marshes Overlook

Photo by Bob McGuire

Out below you lay the Knox-Marsellus and Puddler Marshes, surrounded by grassland and farm fields.


The water and wildlife here change with the seasons—possibly more noticeably than other areas around the refuge.


As the spring migration progresses from March through April, waterfowl—especially snow geese—take advantage of the emergent marsh habitat for resting, feeding, and beginning mating rituals. Sandhill cranes also frequent the area—either at water’s edge, in the surrounding fields, or flying overhead with necks and legs out straight. Great blue heron can be seen here spring through fall; when they fly, their necks are tucked in and their legs are out behind them. Other marsh birds, like black-crowned night herons, may also use the area to create a rookery for nesting. 


Over the course of late spring into summer, water levels in these pools drop naturally, often exposing areas of sparsely vegetated soil, which we call mudflats. These areas provide excellent feeding habitat for migrating shorebirds. Local birding experts and birding clubs volunteer their time and knowledge to give guided shorebird walks during July and August. Check at the refuge visitor center for dates and times.