The list of events for Wisconsin Masters does not show this event:
www.swim-wimasters.org/.../page.cfm
Nor is it listed (so far, anyway) in US Masters Swimming calendar of OW events: www.usms.org/.../event_search.php
If you scroll through the Wisconsin LMSC forum, you'll probably find announcements from the person (organizer) of previous years and perhaps could send him a PM.
