BELOIT – Imagine a single flock of 20,000 geese taking flight from a wetland and filling the sky above your head with wings and clamor. Anyone in southern Wisconsin can experience that and so much more with a lovely seasonal drive to Horicon Marsh. For an amazing evening earlier this month, former Horicon naturalist Bill Volkert brought the vast wetland’s best and worst moments in history to Beloit. Volkert was featured speaker at Green Rock Audubon’s annual meeting and dinner in Bushel & Peck’s Local Market. From prehistoric animals and Ice Age trails to nearly complete ruination by man, over and over again, Volkert hit home significance and import of the largest fresh water cattail marsh in the United States. “Horicon Marsh is one of the most important stopover areas for migratory birds in the Western Hemisphere. Volkert is the author of numerous publications and the recipient of many awards, most recently a 2012 Milwaukee Audubon Society Special Recognition Award and a 2010 National Wetland Leadership Award for Education presented by the Environmental Law Institute. Volkert worked for Wisconsin Department of Natural Resources for 27 years as a naturalist and wildlife educator at Horicon Marsh. For the Green Rock Audubon Society, he gave an overview of the geology, history, wildlife and ecological concerns for maintaining the health and integrity of the vast wetland. The water basin that surrounds the Horicon Marsh is much more vast, Volkert said, and it is under increasing developmental pressure, threatening the vitality of the marsh’s future.