This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu.This project has been supported in part by a grant from the National Trust for Historic Preservation. Acknowledgement is given to Mary Humstone and Michael Matts of the National Trust for Historic Preservation, Robert Puschendorf of the Ne- braska State Historical Society, Larry Reed of the State Historical Society of Wiscon- sin, Sandra Hatter, Cheryl Burkhart-Kriesel, Bruce Treffer and Chris Carlson of Ne- braska Cooperative Extension, and Shirley Niemeyer and Thomas Silletto of the University of Nebraska for their critical review of this publication
