Monmouth County is located in the central portion of the U.S. state of New Jersey. It is bordered to its west by Mercer, Middlesex and Burlington Counties, to its south by Ocean County, to its east by the Atlantic Ocean, and to its north by the Raritan Bay (sharing a border with the boroughs of Staten Island, Brooklyn, and Queens in New York City, across it). Monmouth County's geographic area comprises 30% water.
About a mile long, in the Assunpink WMA. To the east you can find two other small lakes in the same watershed: Stone Tavern Lake, and Rising Sun Lake. Assunpink Creek drains into Lake Mercer, which is much larger than any of these.
The marker in the lower-center of the map is a super-easy put-in on Whale Creek, above. The other markers are a longer slog over the beach. All have convenient free parking (don't leave your vehicle in the launching area, that's a dick move!)
This lake has a lot of different branches to explore, and you can actually go quite a long way. The two marked sites are the best accesses for the northern and southern branches of the lake. Unfortunately, located in the middle of Asbury Park, the water is not the cleanest, especially near the railroad and toward the drain at the beach. The 'headwaters' are better.
This site varies, depending on when you go there. During the summer, and especially on weekends, there can be a lot of motorboats around. Other times, you can have the whole place to yourself.
Lake Lefferts is a man-made lake, the result of the construction in 1928 of Lake Lefferts Dam, which captures and stores the flow of Matawan Creek. This is the nicest spot in northern Monmouth County. The lake is in three parts:
The lower part that contains the dam and the launch area and extends up to the Route 34 bridge. This part is fairly deep and free of obstructions.
The upper part from Route 34 to Route 516. This part is much shallower and weedy, especially at the far end.
An unusable section beyond Route 516. This part is pretty much just mud. It may look like water, but trust me - don't go there.
Marlu Lake - Tinton Falls ( 40.334630, -74.153542 )
More of a pond than a lake, only about half a mile long, but accessible in Thompson Park. Never actually been there. Nearby Swimming River Reservoir is completely off-limits, even to the people that live on it!
The Navesink River is more like a big brackish lake, except where it narrows-down and connects to Raritan Bay. While it is tidal, most of the river has negligible current, although it is wide enough to get choppy if the wind is strong. The water is generally clean, unlike the nearby Swimming River. Boat traffic is not too bad either.
Prospertown Lake - Jackson ( 40.134967, -74.457789 )
This is a nice clean lake that straddles the border between Monmouth and Ocean Counties. The neat thing about it is, if you scroll the map to the upper-right corner, that is not some industrial park, that is Great Adventure! This is the lake that is at the back of the park. At the east end of the lake, you are looking up at all the rides, while to the south is the Safari Park. You can see more water from there, but I wouldn't jump any of the dykes, as that would put you on Great Adventure's property, or maybe in the lion pen. It's not a big lake, but there is plenty of shoreline to inspect. There is a small dam at the western end. No real facilities, just parking.
