[Mountain Escape]

I think if something came loose in the upper drive train, the engine would be making a horrible noise and failing in short order. Iv'e see connecting rods punch holes in the block, but yet to seen anything punch a hole in the valve cover.

I agree with you Dwight, I think somebody dropped something on it, or hit it with something… The only thing that I would be concerned about is the hunk of plastic is now down inside of there

I had oil spewing all over the place!

Yes, the oil filler cap was off in the pic because I was in the middle of an oil change when I noticed the big hole in the rocker cover (front part).

I think your JB Weld probably fixed it blowing oil, Shari.
there should not be too much pressure behind that cover.
To get it done correctly, you would actually have to remove the cover, and make sure it was 100% clean before using the JB Weld
it probably won't stick too good otherwise.
first picture shows a little tiny hole, did you poke at it or something to make it as big as it is?
Point being, all that debris is now inside of your cylinder head, clogging oil galleys, banging against your lifters, and possibly working their way down to your valve seats. You're going to have to pull the cover, and clean it all.

 

[Mountain Escape]

I was told it is part of the rocker cover, however, I can not find a picture of a replacement part that looks right.

I would say first thing you need to do is pull off the plastic cover that covers the top of the engine, and see how much of that valve cover damage extends beyond what you see

Search your year, make and model, along with your engine, and you should see it listed.
I am seeing this, and it looks like you if you are a 3 L V6

https://www.partsgeek.com/hcggtpb-ford-escape-valve-cover.html

200 bucks new. You might be able to shop it now that you have a part number. There are often deals for the whole set, including gaskets on eBay.
If the one is dry rotted, I would strongly suggest doing the pair.
In the event that they dry rot, I would not use scrapyard parts.