On our family cattle ranch in Ola, ID there is an 1880's era orchard (planted by a great grandmother). Most of the apples are inedible/hybridized at this point. But at the very edge of the orchard is a smaller tree that produces small green sweet apples, which ripen by late June/early July. The oldest living relatives all remember picking apples from this particular tree as children, so the tree is at least 50-60 years old. The tree looks healthy BUT has trunk rot, and could topple in a mild windstorm.

This tree does NOT look like it was planted in the same grid as the other trees, so perhaps it came from seed. We don't know.

Does this tree sound special enough to try and take a graft / scion from? If so, what are our chances of doing this now (July) when the tree is in full leaf? We're worried the tree won't last another winter. There is new growth, but not a lot.

This is USDA zone 6, I think. Is the June ripening a special characteristic for a heirloom apple?

You will have to wait for the experts for more about the tree, but you may want to try bud grafting it this August. There is an overview on budding in this article:
http://www.homeorchardsociety.org/article/19/

Not many apple ripen in July or are hardy for your Idaho loctation.
One guess.
'Yellow Transparent' some of its charactersitics are:
Fruit Size/Shape
Above medium to large, round oval to round conic or oblate conic, slightly ribbed, sides unequal. Heavy set may require thinning to increase fruit size. Stem medium to long rather thick.
Skin
Pale yellow changing to yellowish-white, thin, tender, smooth, waxy. Lenticels numerous, light colored, often submerged.
Flesh
White, moderately tender and bruises easily, fine-grained, crisp and juicy.
Flavor
Sprightly subacid, pleasant but not highly flavored.

Anothe guess 'Lodi' some characteristics are:
Size and Shape
Large, conical. Stem long.
Skin
Clear yellow when fully ripe
Flesh
White, crisp, and juicy.
Flavor
Mildly subacid, sweet-tart.

If you like it it can be saved as Steven said by budding.


Ted