Article written by Calvin R. Fremling regarding a specific mayfly emergence on July 8, 1966 at Winona, Minnesota. Includes locations around the city such as Levee Park (emergence resulted in a shutdown of carnival equipment operating for Steamboat Days) and the John A. Latsch Wagon Bridge. Figure 1 shows a heavy swarm of mayflies covering the bridge and the author\u27s car. Summary: This report documents a mass Hexagenia mayfly emergence from the Upper Mississippi River, so that others may know of the magnitude of the phenomenon if Hexagenia populations are further reduced by pollution along the Upper Mississippi River. Fremling is credited as: Winona State College, Winona, Minnesota. Article reprinted from Transactions of the American Fisheries Society, volume 97, number 3, 19 July 1968. 5 pages. Part of the Cal R. Fremling Collection.https://openriver.winona.edu/calfremlingpapers/1021/thumbnail.jp
