This is a strange one that sounds more like an urban legend whipped up by some UAW grunts in a break room one night. But it seems to be true by all accounts, though I doubt you will ever hear any authorities verify it on the record, especially Ford Motor Company or the Ford family. As Henry Ford himself once famously said, "History is more or less bunk.”
In a weird pocket of swampy woods in Dearborn Heights there is a rotten old ruin of a mansion tangled in the woods, once known as the "River Oaks Mystery House." I myself didn't learn the full breadth of its wacky history until after I had explored it.
Here' goes:
According to The Novi, an article by Dick Ralstin about an experimental 1934 Indy race car, a man named Raymond Dahlinger worked in the Ford Development & Engineering Dept., and collaborated in the development of the famous Flathead Ford V8. This Ray Dahlinger was a close friend of Henry Ford, and I have heard that he was also Henry's personal chauffeur. Henry Ford, who was married (to Clara Ford), took a shine to a Ms. Evangeline Cote, and the two became "romantically entangled." In fact, they are supposed to have bore a son in 1923. It is rumored that Henry Ford asked Ray Dahlinger to marry Evangeline as a favor, in order to give the illegitimate child a proper father, and the mother a provider...hence a better, more socially appropriate life for the two. It would also help obscure Henry's naughty little boo-boo.
Evangeline's maiden name was Cote, and she was the daughter and sister of the owners of the Cote Motor Company, based in Ferndale (just north of Detroit), which incidentally sprung up right after she gave birth to Henry's illegitimate son (seemingly almost as a form of dowry to their family from Ford). The child, John Dahlinger, was raised by Ray Dahlinger as a son, and lived a strange life of semi-privilege, wherein he was a (semi) beneficiary of one of the most powerful men in the world, Henry Ford. Yet he was still also just that mysterious black sheep offspring that was always lurking on the periphery of the Ford family but had no claim to the line of succession in the company.
For instance, he was promised a fat inheritance upon Henry's death (though he got stiffed in the end), and he was often given strange gifts...such as for instance when he turned seven, he received the winning car from the Indy 500 as a present. The actual car. When he started school (a school coincidentally built by–you guessed it–Henry Ford), John also was allowed to use the old school desk Henry had used as a boy. There are also pictures of John playing with the Ford grandchildren, who were the same age as him.
The Dahlingers also mysteriously received a brand new mansion on Ford-owned land, right upriver from Henry's own Fairlane Estate. Fairlane and the Dahlinger Estate straddled the Dearborn/Dearborn Heights border, and both houses sat on the banks of the Rouge River.
The unofficial Ford historian, who coincidentally enough is named Ford R. Bryan, mentions the Dahlingers in his book, Beyond the Model T: The Other Ventures of Henry Ford. Bryan has written six books on Ford. Evangeline Dahlinger remained Henry's mistress for some time, and was said to have had quite a bit of influence behind many of Henry's business decisions, such as the development of Greenfield Village.
It was no coincidence that the Dahlinger Estate was built right on the Rouge River, just north of Henry's own pad. Henry orchestrated this so that he could slip away and sail his boat up the Rouge, and sneak into her place for a quick rendezvous, then sail away, back down the river.
John Cote Dahlingers Book
The Secret Life of Henry Ford
John Dahlinger himself described this in a book he wrote in 1978 entitled The Secret Life of Henry Ford, saying that when Henry built the house for Raymond and Evangeline, he had a secret stairway added in, which went from the back of the house up to Evangeline's dressing room.
View of the Boathouse from Cache Location
John writes,
"Before I tell you about the main house that Ford built for us, I'd better let you know that Mother was a fireplace freak, as the young would label her today. The main house has nine fire-places, one more fireplace than it has bathrooms. It also has a four-car garage with a mechanic's hoist so that a Ford expert could come and make repairs on the spot.
There are comfortable servants' quarters, and a flower room, where flowers could be arranged for the other rooms without messing up those rooms. There is a refrigerated fur-storage vault. There was a room for an indoor pool, which, however, could never be installed, because the Rouge River would overflow and cause drainage back-up.
There is even a secret staircase. It is hard to know whether even Dad knew that this secret entrance to Mother's dressing room was being installed. This is indeed the major secret of the house. A person could go into a certain small room downstairs and disappear into the secret staircase that led up to Mother's suite. One could also leave the same way without being observed.
Mother had at her disposal the Ford craftsmen, many of whom had been brought from Europe to work at Greenfield Village–including woodcarvers and iron smiths. The house was her magnificent obsession. She kept changing and revising the house plans.
Sometimes a wall was torn down and moved a foot in one or the other direction. Once, when she changed her mind, all the furnace ducts had to be moved to conform with her revised wishes, and the furnace men had to be called back.”
Ms. Evangeline Cote Dahlinger & infant John
Ford R. Bryan's book says:
"In his book Dahlinger describes that the home that his family lived in was built for them and then sold to them for the sum of $1. They bought 150 acres to make the transaction legal. This estate has always been known as the Dahlinger estate including a gate barn with a 24-hour guard, a Kentucky show barn, a working barn, a single-story stall barn with corrals, a blacksmith's shop, a lake with skating house, a quarter-mile cinder track, a 6-car garage, a beautiful middle sized house, a greenhouse with servants quarters, a boathouse, a farmhouse with 3 garages and a main house. Because his mother, Mrs. Dahlinger, was in love with fireplaces there were nine in the main house.”
As you can see, the "Mystery House" is quite decrepit today, and almost unexplored on the interior. I cannot say that I saw a "secret" stairway, though to be fair I was not looking for one at the time, and there is a good chance it rotted away anyhow. I am also not sure whether this is the actual house or the "middle sized house," or what has been demolished versus what remains.
What I can say is that it certainly was set up oddly. Before I knew the real story, I had already come to the conclusion that it was owned by a very eccentric person. Strangely enough, there were a couple rooms that were absolutely filled with automotive junk.
In November of 2013 John Dahlinger's son, John Cote Dahlinger Jr., was murdered in Grand Rapids, Michigan. A Detroit Free Press article rehashes the story of Henry Ford's illegitimate son, though it does not seem his lineage had any bearing on the murder.
Under this foundation here was what looked to be a bricked-up and back filled tunnel. There was a definite "thing" with Henry Ford and secret tunnels and passageways. There is of course the rumor of an escape tunnel leading out from underneath the Rouge Plant which Henry had built for himself in case of another labor riot like the Hunger March of 1932, or an assassination attempt on his life.
Henry was a well known escape artist; by that I mean it is documented that he went to lengths to ensure that he would never be cornered in his office with someone he didn’t want to talk to. He liked being able to disappear whenever he wanted, to get away from the press, or whoever he was currently at odds with.
Current Google Earth View
Hearsay, but take it for what it is. Tall tales about the early auto barons are common, but no one had more rumors swirling about him than Ford. Even Ford's head security man and bodyguard, Harry Bennett, had a mansion in Ypsilanti with secret passages, known as Bennett Castle. He even had fake trees in his yard which were made of steel, and hollow with stairs inside, so as to be sniper posts.
References:
The Secret Life of Henry Ford, by John Cote-Dahlinger
Ford: We Never Called Him Henry, by Harry Bennett
Rouge, Picture in its Prime, by Ford R. Bryan
http://www.nailhed.com/2014/01/henry-fords-other-son.html
http://www.retrokimmer.com/2013/01/ray-dahlinger-henry-fords-secret-life.html