But assuming that is not possible, here are some details we need to know.
First, where are you located? Some apples might not be usually grown in all climate zones.
Second, do the apples on all 4 trees look identical? Are they the same size on all the trees? Same color at this point? Do the trees themselves have similar shapes? It would be more usual, if there are just the 4 fruit trees, for a backyard orchard to have different varieties to enjoy different flavors and have apples ripening at different times. I am assuming that these are 'backyard orchard' trees, not a remnant of a former commercial orchard.
Next, how old do you guess the trees are? How tall? How old is the house? If the trees were planted 40-50 yrs ago the list of suspect varieties will be different than if 10 yrs ago.
Last question-when do they get ripe and what color and size and shape are they then? Ask a neighbor if you can't reach the planter. If no one can answer then you might need to wait till they do ripen.

One last suggestion assuming we can't answer immediately-once they ripen ask your mother-in-law, the expert dessert baker, for her help in figuring it out by tasting and testing out some of the fruit in her pies etc. Never hurts to ask a MIL for help in a way that acknowledges her expertise in something! Offer her plenty of them! ('Mom, I would love for you to have a chance to test them out when they ripen to see it they are good apples for pies or cooking')

Good luck! And it looks like you might have some nice apples there

If you aren't able to bring apples to be I.D. then here is a link from our own group who has set up framework for you to do the detective work:

http://www.seattletreefruitsociety.com/appleid.php
Q

Unless you're a scientist with knowledge and easy access to DNA analysis techniques, you won't be able to determine what variety your apples are until they ripen, and even then it is only an educated guess.

1. I live in Central Minnesota
2. The tree is roughly 13ft tall.
3. The house was built in 1989.
4. Trees are about the same size with the same size fruit as of now.
5. It is just a backyard orchard. (If you want to call it an orchard)

Again, I'll probably have to wait til fall to find out but maybe someone will have an inkling. Thanks again everyone.

Since the apple is ripe now and you are in central Minnesota I will assume it is some early ripening cold hardy variety. Beacon? Not sure from the picture.

If this tissue browing occured on later season apples in
storage it would be from a calcium issue (water core, internal cork).

However I have seen this sometimes on summer apples.
Some years they are great and other years the fruit looks good but the flesh is all brown. Many years ago
I recall picking Viking in late July. One year it was good
and the next year I picked none as all were brown inside.

Another issue is that some early season apples do not keep long. Good examples are Beacon and Yellow Transparent. Great for 3 days then turn to mush.

Are all the apples on the tree like this? Just wondering if
they are over-ripe or if it is some calcium issue? I am not sure. Just my thoughts on some possibilities.