Help identifying vine or weed?

Has anyone ever seen this plant before? It grew very quickly and is taking over a small evergreen plant. I have to relocate the tree now but not sure if this is a vine worth saving or a weed I need to remove. Any assistance would be appreciated. I am attaching pictures of it. Thanks!

 

Looks like the grapevine, Vitis vinifera. One of fast-growing variety, probably, Concord.

 

Menispermum canadense I believe.
http://www.duke.edu/~cwcook/trees/meca.html

 

Menispermum should not have tendrils:

http://www.illinoiswildflowers.info/trees/plants/moonseed.htm

 

But not Concord - leaves are different.
This is Concord from my backyard:

 

Vitis labrusca, may be:
http://www.illinoiswildflowers.info/trees/plants/fox_grape.html

 

First thought was that this is Melothria or a relative in Cucurbitaceae family.

 

Perhaps Sicyos angulatus which ranges that far North?
http://woodisfun.blogspot.com/2010/08/burcucumber-sicyos-angulatus.html

 

I thought about Sicyos angulatus, but on most images it looks too hairy, whereas this vine is perfectly glabrous.
On the other side, Sicyos may have two tentacles per node as in this vine. Most of images of grape and Melothria where I can count tentacles show just one per node.

 

Thanks for all the responses. It does seem to be a mystery. I just re-examined the plant thoroughly and there are no buds or flowers on it, just leaves. Here's another picture of one of the tendrils coming off it. I guess my real question is - is this a weed I should get rid of or a vine I should relocate?

 

I would keep it just of curiosity to see what comes from it. Relocation may kill it anyway. You can leave one-two branches until they flower. The evergreen definitely needs rescue - it is very sensitive to shadowing.

 

Passiflora?

 

This is surely a curcubit, out my way the plant that looks like this is Marah oreganus.

 

So close! I checked out a few pictures online of Marah Oreganus and found this picture that is extremely close. Only problem is that Marah Oreganus is only found on the Pacific Coast. It's probably in the family though. I tried to find other manroots that are native to northern Vermont but not much luck. Once again, thanks to everyone for your responses!

 

Echinocystis ?

 

I've seen that last one identified more than once as the plant being asked about in posts originating back east.

 

Yes, likely Echinocystis lobata.

 

Daniel, that sure looks like it minus the white flowers. I don't know how long it will take before they show up but I'll be sure to let everyone know! Thanks!