Personally, I'd risk a damaged fence for the sake of seeing woodpeckers at work. Different matter if it was the house, I suppose.

Is 'snag' a local term for a dead tree? I've not come across it.

'Snag' - "In forest ecology, a snag refers to a standing, dead or dying tree, often missing a top or most of the smaller branches. In freshwater ecology it refers to trees, branches, and other pieces of naturally occurring wood found sunken in rivers and streams; it is also known as coarse woody debris."

In my area, we are encouraged to leave snags standing, especially in the more forested areas, as they are considered a desirable wildlife habitat. Some have been in place for decades. But I would always consider proximity to a structure to decide whether to leave intact or remove.

I did some reading,
the snag appears to be between stage 3 and 4, some but not all of the bark has
loosened. Looks like I have several years until stage 6 where pieces break off.

Successional
stages of a snag from death of a tree to final decomposition. From https://en.wikipedia.org/wiki/Snag_(ecology)

A 20' tree should be pretty easy to cut down by yourself. In that early stage of decay it can still be good firewood

Interesting. I'd not come across the term used in that way. I've since found it (in brackets) describing standing dead wood in some specialised forestry publications. Quite an interesting read if you have some time to spare.

In Oz, a "snag" is slang for a sausage...never seen one 20' long, though.

Thanks for the caution! There is no way to ID the dead tree now, but I peek over the fence in spring and look for signs of decay at the base.

FWIW, I have a 3' tall tree trunk without bark that I have used as outdoor decoration for close to 2 decades. The only decay is at the base after I put it on bare soil for a couple of years. I have since elevate it off the ground and there is no noticeable decay since then.

My neighbor in the back had the snag cut down. No more woodpecker watching :-(

Looking at the stump, there is no sign of any rot, there would have been no danger for the fence close by for a long time to come. With the big snag out of the way, a small snag of about 7' tall became visible at a different neighbor in the back (no danger to anything)

Makes me wonder if that general area is diseased, ouch, other trees nearby are healthy, though. The two snags must have been standing there for many years.

I am getting quotes from a few arborists to remove the top two-thirds of a dead pine in my yard. I told them all I wanted to leave a snag and one of those arborists did not know what a snag was, so you were not alone floral.

tj