Eastern Oklahoma is large area. Do you have a specific location?
I remember lots of mulberry trees.
This is from tulsaworld.com:
Generally, apples and pears are the easiest of the tree fruit to manage, with peaches being the most difficult. Sweet cherries do not thrive in Oklahoma, but sour cherries do well. Most of the berries require much less management and can be grown more successfully than the larger fruit.
Your profile says: Rocky Mountains, I would recommend if you are planning a move to East Oklahoma check with the local County Extension Agent as I am sure you can get answers there.