From this story on nj.com:
A fisherman's paradise, Round Valley Reservoir in Hunterdon County stretches across 2,000 noise-free acres and is stocked with plenty of trout. On a good day, you can gaze down about 20 feet into its blue waters. But there's also a dark side to the popular Clinton Township fishing hole, New Jersey's deepest man-made lake. Somewhere in its depths lie six presumably drowned men who've been missing for years, and surrounding it are tales about its death toll, which numbers roughly a couple dozen within the past 40 years.