Did it have any thorns? If so, it could be a quince.

Not quite enough information there.
Is the fruit pyriform or bell shaped or oval? What is the color and size of the fruit. When cut open does it have a fragrance and what is the seed pattern: do they look like apple seed or rose seed or is it a single seed? What do the leaves look like (shape)? Are they alternate or opposite?

Thanks for responding... there are no thorns...I am trying to get some of the fruit to my house for further examination. The only thing I remember about the fruit was that it as a hard, green, fuzzy fruit that everyone else thought was a pear. The tree was about 15 ft high. I will get back later with more desciptions. Thanks, everyone!

I don't suppose it looked anything like this, did it?
{{gwi:833622}}

what the heck is THAT?

I've got a feeling it's not going to be a fruit in the traditional sense but a seed pod. We'll just have to wait and see.

when i roll the mouse over the picture, it tells me what it is.

LOL!!! Gotcha, Lucky!!! Well done, HGSB!

I wouldn't be at surprised if it does end up being a black walnut, at this time of the year! My guess is that the original poster didn't even take a look at the leaves, but only the fruit.

Dorie,
HGSB got me, all right, but it's not a black walnut. I guess I'll buy it as being J.regia - that dark, conical bud up at the attachment of the stem to the branch is believable as a J.regia bud, but it ain't J.nigra. I'd just never (until now) seen a developing Persian/Carpathian walnut on the tree - all of my seedlings & grafts are still too young to fruit.
But now my question is - are those brown squiggly tracks evidence of walnut husk maggot infestation?

Welllll there's a bunch of those around around here and the fruits look like that. They have the signature residue-on-the-hands that black walnuts leave so I figured it was the same.

Any pics of the leaves/bark/habit?

I finally have the fruit in hand. It is pear shaped, very hard to cut in half, seeds are in a tight circle in the middle. Leaves on the tree were opposite. Definitely not a black walnut. I am going to take it to the extension office tomorrow, maybe they have seen it around here before. Thanks.

Might be a seckle pear. They don't ripen until late fall.

Someone told me that this tree is called a "hedge apple" or "devil's fruit" (hence, the poisonous theory). She said that was all they had ever known it to be.

Forget the hedge apple theory. I saw a picture of those &
what I have isn't remotely similiar. The one I cut up had the same dark mealy "stuff" around the seed that I've seen in pears off old pear trees around here.

not sure if westender was referring to the fruit of a flowering quince (chaenomeles sp.) or not but perhaps a real quince, cydonia oblonga?

Here is a link that might be useful: quince fruit

My county extension agent just called and confirmed... it is a quince. Jeff hit the nail on the head! It is exactly like the picture! Thanks everyone!