Here's what I know about the apple:
As you can see in the photo, the apples are light yellow (some have a greenish tint, and some have a few red spots). They're about 2.5" across. Their flesh is super snow-white and is very hard/crunchy. The flavor is absolutely wonderful. We bought this place 2 years ago, and all we know is that first, Swedish, and then Finnish immigrants planted about 20 different apple trees on the property in the 1920s, 1930s, and 1940s. The tree is not large (maybe 25' high and 30' wide), and this apple is by far the last to ripen--apples are just now starting to fall. (On all other apple trees there but one (a tasty small red mystery apple tree), the apples have all fallen and rotted by now.)
I know that apple ID can be next to impossible. But several folks have told me that some apple experts can ID an apple by photo and description.
THanks for any thoughts,