Lynn,
Dead River is just an abandoned mega-meander of the ancient Great Egg Harbor River – an oxbow. The toponym is well and alive in the oral tradition. I don’t remember ever seeing it put on a map, but many a paddler have taken a wrong turn to arrive at a dead end.
Mare Run (OED: means "a female horse"
or "a frightening place") is very old, and can be confused with Miry (OED: means “full of mud”) Run down at Catawba. Ireland’s Mill was built near the confluence of Mare Run with the Great Egg Harbor River. I suspect today’s Watering Hole bar at the mill location might have been the second furnace-era tavern in Emmelville, its pair the brick tavern still standing as a private residence up the road and across from the campground.
Near the Mare’s head by Gigantic City was Blue Bent (OED: means “curved”) Pond, a perfectly circular spung that has long since dried up, as have the great winter ponds at the Lochs-of-the-Swamp. The c.1706 Steelman Plantation was nearby at the intersections of the Long-A-Coming and Cohansey trails, so Europeans were in the area very early in history.
.
Excerpt of Denny (c.1773) resurvey of the West to the West Jersey Society as copied in Clement (Volume 1, page 16, Historical Society of Pennsylvania).
S-M