#2: Kilcohook Coordination Area

I grew up in New Jersey and have spent my entire life being fascinated by maps, so one of the strangest bits of geopolitical marking I've ever seen was also one of the first I noticed. That's because it appears on the New Jersey map - a strange little nub northwest of Salem that sticks out into the Delaware River estuary. This nub, marked on my 2009 road atlas as the "Kilcohook Coordination Area" but known to Google Maps as "Killcohook National Refuge," just happens to belong to the state of Delaware.

Google Maps view of "Killcohook National Refuge," with the dashed line demarcating its separation from New Jersey on the river's east bank and alliance with Delaware to the west.

So how to explain this oddity? In 1732, Lord Baltimore met with representatives of William Penn's family to set the border between Pennsylvania and colonies below it. What is now Delaware's northern boundary was determined by a 12-mile radius extending outward from the New Castle courthouse.

Such a radius also technically gave Delaware claims to land on the New Jersey side of the river. These claims were never seriously pursued, but Delaware did maintain a claim over the entire river; while usually water boundaries fall down the middle of the body of water in question, the original 1682 land grant to William Penn included the entirety of the river up to the New Jersey shoreline. (The grant was cited in a recent Supreme Court decision that allowed Delaware to block industrial development on the New Jersey side.)

Of course, none of this would have anything to do with Kilcohook were it not for the Army Corps of Engineers. The Corps was involved in dredging the lower Delaware River in the first part of the 20th century, and the massive amounts of silt and mud that resulted had to be put somewhere. They ended up on the New Jersey side of the river - but because Delaware laid claim to the entire river up to the low tide line on the New Jersey side, they also laid claim to any land generated by the Corps on the river's side of the old low tide line. Kilcohook was the result.

This 1777 map of the area shows no Delaware territory on the New Jersey side. A map of Delaware from the early 19th century also shows no territory across the river.

In 1934, the government declared the area a National Wildlife Refuge; however, the status was revoked in 1998 because the land was too much of a dump for the Corps and not enough of a refuge for wildlife, explaining why current maps call that bit of land a "coordination area."

You can actually visit Kilcohook; while the area is technically supposed to be off-limits, it seems not to be guarded and hikers and bikers can easily enter (though car traffic cannot). Of course, it's not exactly Point Roberts; a reporter for a local ABC station visited Kilcohook and described it as looking "like one big construction site, without the wood, cement and bricks." New Jersey sure doesn't need any more construction sites. Enjoy, Delaware!

Non-linked references:
Information about the courthouse radius from http://www.nps.gov/history/nhl/designations/samples/de/NCCO.pdf, pages 8 and 9
1777 New Jersey map from http://mapmaker.rutgers.edu/MAPS.html
Mention of the Corps of Engineers and the dredging of the river at http://www.wdel.com/blog/?postid=1277
Killcohook NWR info and "construction site" quote from http://abclocal.go.com/wpvi/story?section=news/local&id=4874172