The drainage of your soil is not only affected by the clay and sand content. It is also influenced by mineral content, slope and the possible change of character in the sub-soil.
I once had an apple tree that vexed me. I had planted it in what appeared to be a spot with sandy soil. Yet it sulked and suffered as if it was planted in a giant wad of clay. After the tree died, I dug it up and inspected its roots looking for a cause. It was when I dug down to the bottom of the root ball that I discovered the problem was a thick layer of clay three feet below the surface.
Fruit trees need proper drainage in order for them to maintain aeration around the roots, expand their roots and gain access to nutrients that trickle down through the soil from the surface. If the soil is water logged and the tree cannot process the water, it becomes impacted. The tree starves from a lack of nutrient transfer of it can suffer root rot.
You should be suspicious of a change in sub-soil character if you live near or in an old river or creek basin. Rivers move a lot over the course of geological time, over the course of a century they can deposit conflicting layers over top of each other. If you are in one of these regions I advocate digging down to around 5 feet just to make sure there isn’t some kind of change in the sub-soil.
You can get an idea of how well your soil drains by digging a hole the size of a 5 gallon bucket. Fill the hole with water. Wait one hour before checking it again. If the hole has completely drained out you are probably in an ideal location.
Fill the hole again with water. This will represent the effect of a period of heavy summer rains. If the hole hasn’t drained in three hours the soil might have too high of clay content or too poor of a slope for you to grow fruit trees.
You could still grow berries in that location, though. If you wanted to explore landscaping options you could rent a backhoe, dig the area out and bring in a load of sandy soil to fill the hole. You could build a raised planter box, or even install underground drainage pipes that would act like drain tile. In either case if you are concerned that you have too poor of drainage in your soil, you can call the county agricultural extension office for further insights.