I have a very friendly volunteer fruit tree which is glad to grow in my yard. It is producing some of the strangest fruit. Whenever a tree pops up in my yard I always prune it and let it grow.

I'm in central Washington in Apple country. My property is an old homestead and orchard so there are always apple trees volunteering, but this tree threw us for a loop. It's certainly not an apple. I'm leaning toward peach but it's not fuzzy. Nectarine?

I've been pruning the suckers and doing what I can for this volunteer. It's been thriving like no other tree in my yard.

Can you help me identify the tree?

It look like walnut (Juglans regia)

Edit : https://en.m.wikipedia.org/wik...

Yes it does look like a walnut. If you have to have a strange volunteer fruit tree, I think that's a good choice. The husks will open and the walnuts fall to the ground when they are ready to eat. That will happen next fall sometime, depending upon variety. In California, they tend to fall after a rainstorm.

Walnut (Juglans regia)