I'm trying to recall...

I've seen a picture of a railroad junction or diamond that was located in the middle of a lake. it could have been a marsh of sorts. The location could have been MN, WI, IN, or in the general region. The tracks were of milder importance, but the crossing had to be located off-shore due to some kind of surrounding geographical/suburban entity blocking a cheaper crossing. Obviously, one railroad was there first, and the second railroad was forced to cross it in the lake. If I recall, the crossing is somewhat famous in the area, and about ten years ago saw people wearing T-shirts for a railroad related event there. Are the tracks still in service? Who's tracks were they?

I'm being a little vague with my questions, I hope that someone can help me obtain some info on the subject.

almo