Named the "Henley Oak" near Covelo, CA (at an elev. of about 2000 ft. in Round Valley, Mendocino County, south of Ukiah). It's North America's tallest oak (over 140 ft.), with a CBH of about 32 ft. (9.8 ft. DBH).

Himy mackerel. huge trunk

Looking at the picture, that's a big one. I've seen many valley oaks (Q. lobata), but none that big. The biggest I've seen were only a little more than half that diameter. The one in the picture seems as wide as the coastal redwoods. Judging from the picture, I'd estimate the diameter to be between 11.5 to 13.5 feet.

(For comparison, the biggest oak in Missouri is only 7.5 feet in diameter)

Those oaks have deep roots, so can pull moisture up out of the ground even when the topsoil dries out at the end of May.

another thread to read up on: I just planted "the largest (growing) oak in the world" (posted by artinnaturez8b, July 25, 2025)

There is an update, a possible correction to the information about the picture in the opening post. It seems there has been some confusion. The oak shown in the picture may be located in Groveland, rather than being the Henley oak near Covelo (according to one comment).

link to Facebook picture

The person who posted the picture on Facebook was not the one who took the picture, and later corrected the caption in response to one of the comments.

However, I've scoured the internet looking for any information or pictures of a huge oak tree in Groveland and have been unable to find anything. So it may perhaps be possible the person who left the comment was also wrong.

I did a quick look over of satellite imagery of Groveland, and I cannot seem to identify any of bigger tree that is in a location that would be consistent with the background in that picture. (It's not as difficult as you might think since the lush greenery (and biggest trees) is all concentrated in the smaller valley where the town is in and much of the land has been cleared) I could of course be wrong, but that seems like one more indication that this tree might not be in Groveland. I looked at several street view pictures in Groveland, and this oak tree in the picture just seems like it would be out of place there.

So it looks like it may still be a mystery where the tree in the picture is.

The problem with pictures posted to Facebook is it plays havoc with trying to use tools to do a search to see where the picture first appeared.

It's a long stretch but I did find this picture that the person says was taken in Tehachapi, which I feel could have a possibility of being the oak in the picture, if the picture had been taken from the other side. The people commenting say it's a Valley oak.

Big Tree Seekers | Facebook

Socal, it was indeed big tree seekers on FB where I got the pic. And yes, sometimes there are (prb'ly unintentional) mistakes made in location and sometimes even species.