We put in on the east fork of the Rock River at Greenhead Landing just west of Mayville. We kayaked west to about the middle of the marsh and returned back to Greenhead Landing. The landing was a very easy place to launch and park the vehicle at river's edge.
There was very little current in the river, but lots of wind when we got into the cattail marsh. The first part of the river had trees and brush on the edges, but when we got into the marsh there were only cattails on each side.
We saw several flocks of pelicans, Sandhill cranes, sandpipers, and an Osprey.
From the city of Horicon take 28 northeast to Bayview Road. Turn north on Bayview and after about a mile turn west on Greenhead Rd. In about a half mile Greenhead will turn right and go to the river's edge.
The DNR has a map on line. Check the Horicon Marsh web sites.