Listed as a former alpine ski area in the Otsego County Fact Book.
This page claims to be a satellite view of the former Waters Ski Club site. From here you can go to a street view and actually look up the hill. From a topo site, it looks like the area had about 100′ of vertical.
Indeed it was a ski area. My dad, O.L. “Doc” Smith first went to Waters while attending MSU in the 1940′s. There was a ski train that went from Lansing to Gaylord. At the time Waters had the first rope tow in the area. Ultimately Mt. Frederic and Otsego displaced the one-run Waters. The satellite view is accurate. From I-75 and from US 27 before I-75 was built one had to drive right by Waters. Of course, my Dad recounted his college adventures each time we drove by.
We have since used this hill as a very formidable sledding hill.