I've harvested a few pounds of grapes in the foothills here in CO, but nothing like filling 55gallon drums!
There's lots of wild grapes around, but they are tiny and are super astringent (require lots of sugar), so I've not really experimented with them too much (just mixing them into ice cream mostly). Wild grapes and wild hops like the same areas.
Unfortunately, I don't have the option of planting a vine or vineyard for that matter as I am a lowly renter. Once we get a house, I'll get some grapes in the ground.