Sounds like japanese knotweed, a notoriously bad actor.

Here is a link that might be useful: japanese knotweed

I don't recall that it had many branches (like the knotweed) - it was more like one or two very large leaves at or near the very top of one stalk, and maybe some coloration, maybe reddish. The stalk was quite large in diameter.
Of course I could be remembering the leaves wrong and don't know if I want to let some grow again just to see. I imagine keeping it cut back will be ongoing - like the honeysuckle!

Gardenway,

Please see my posting on ID briars/need to kill Image No. 2....I think you and I might be talking about the same weed. I attached a picture. I also don't know what it is, but if you want to use the picture as reference if its the same plant, feel free to.

Mgan9311

mgan9311 - I think what I have is Giant Knotweed (I didn't realize there were two types of knotweed).

Re your picture - it looks to me like wild raspberry, which I also have. Except I haven't seen any 10 ft tall - so maybe blackberry as someone else said.
Also - I am able to dig them up (when first showing growth) easily enough.

I have tons of vines that are growing in my unmanacured (natural) backyard. They have thorns and grow up the trees.
I tried to pull them up, but they are attached to a thick horizontal root that grows parrallel to the surface. I think it's mapped out all over the yard because there's 100+ of these little sprouts.
My main problem is that we built a deck and they are punching up through the wood! They are out of contol...how do i kill them?

My only suggestion is to keep cutting them down. And any roots you can uncover also cut. You could spray the "stump" and any new growth. I don't think it is going to be a quick process to get rid of.