So This Is The Largest Boulder On Long Island

Yesterday, I was driving along Shelter Rock Road in Long Island on my way back to the city…


And as I was driving, I started to think to myself that Shelter Rock Road is a really interesting name for a street, and that it was too bad I’d probably never know find out what the origin of it was.


Then, literally as I was having this thought, I pulled up to a traffic light and noticed this sign posted beside it:


The biggest boulder on Long Island! Moved here over 20,000 years ago! Used as an Indian shelter in 1,000 BC! Just ten feet from my car! Obviously, there was some kind of weird scouting kismet going on, so I parked across the street and made an insane dash across four lanes of traffic to the iron fence…


And peering through the trees, I saw it – Long Island’s largest boulder:


If you’re a bit underwhelmed, it’s probably because you’re comparing this to the sort of exposed rock face you see all over the place, which isn’t fair to Shelter Rock. At 55-ft by 35-ft and an estimated 5,000,000 pounds, the granite boulder – technically, a “glacial erratic” – was moved to this spot by a glacial ice sheet somewhere between 11 – 20,000 years ago, most likely originating from the Bronx or Westchester.


The Matinecock tribe had a settlement nearby, and the 30-foot overhang is believed to have been used as a shelter. Bits of pottery and other artifacts have been unearthed beneath it.


One neat bit: there are a number of trees growing out of the top of the boulder:


Sadly, the Largest Boulder on Long Island sits just beyond the perimeter of Greentree, the privately owned former Whitney estate, so I wasn’t able to take shelter under its protective overhang (the Greentree Foundation does occasionally arrange for private tours for school and other groups).


And now having unexpectedly learned the meaning behind Shelter Rock, I headed toward the Long Island Expressway, where I was once again reminded that “expressway” and I-495 have absolutely nothing in common.


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  1. On a drive to Montpelier VT I passed a road called “Old Mill Road,” and having noted that roads in Vermont named “Cemetery Road” invariable led to the tone cemetery, I doubled back to pursue Old Mill Road. I followed it as far as I could, to a barricade, beyond which were trees and the continuing road, in disrepair. I walked for what must have been a mile, and never saw even ruins of the old mill. But these things must be checked out.

  2. You got to see Long Islands largest boulder & Long Islands largest parking lot all in one day!! Very nice. Cool find though, I had no idea that was there.

  3. thank you, its my exit to get home, i never thought somebody would think like i do!
    now i have to go find the rock!

  4. There were larger boulders, also glacial erratics, in that area that were destroyed due to development. One in particular, known locally as “Big Rock”, was on the border of Plandome and Manhasset near Manhasset Bay. Shelter Rock has had the good fortune of being protected by Greentree.

    • Where exactly was big rock? I live in manhasset so now you have me curious

      • Steve Lastnamenotgiven

        I used to live in Manhasset in the 60s and went to Big Rock several times. We would walk down The Terrace from Plandome Rd, and when the road made a right turn there was a path that went into the woods and right to Big Rock, and right across from it was another large rock called “Little Rock”.

        I found this site because I fave been looking for photographs of Big Rock but have never found any. It was easy to climb up the front. It was a perfect ramp. I once climbed down the back and got stuck for maybe 45 minutes but eventually got down.


  5. Steve Lombardi

    Then, of course, there is balanced rock in my neck of the woods, another glacial oddity:

  6. One has to wonder how the Indians made it all the way from Asia to this boulder site.

  7. While it is sad that there is no public access to the rock, it’s probably also a good thing as the rock would have likely been covered by layers of graffiti by now had it not been off limits.

  8. And it’s not even made of crack cocaine!

  9. Still a few of these big puppies around in the water, off Old Field Point comes to mind. Agree about the fence keeping graffitti away. Speaking of “graffitti” & underwater rocks, you might want to check along the north shore just before Greenport. There are/were some great rock carvings in some rocks below the high tide mark.

  10. There’s another big rock further east, on Nichols Road at the south end of the SUNY Stony Brook campus.

  11. I live 3 blocks from here! Probably the most exciting thing in Manhasset sadly….

  12. You weren’t too far from Target Rock. Check it out next time you’re in northern Nassau County.