Grapes in Cherry Tree

What's that up in the cherry tree? Grapes! I'm not sure of the variety, possible Niagra. I suggest Niagra as the variety because it is the most popular seeded green grape variety sold in stores, although I bought the original plant at a Farmer's Marker in Vancouver 4 or 5 years ago.
They are very juicy and sweet, but given their locaton 20 or 30 feet off the gound, it takes a ladder to harvest them. The plan was to have them grow along a fence UNDER the tree, but this vine has aspirations of its own.