A section of the cambium layer on the tree trunk was injured and died at some point. The remaining living cambium is growing to cover up and close off the wound. This is normal growth and process for a tree that has suffered damage to the trunk. The wound site is a potential entry point for decay, that is how you get hollow trees, thus a potential weak point in the future.

This is not a death sentence or imminent threat. As long as the tree is happy and doing well, it is young enough and small enough to grow over it and it may never matter. You can get another 40 years from this tree and there is nothing you need to do. It will heal itself.

Thanks for the information. I’ve never noticed any external damage, could it have been some sort of “internal” damage under the bark? Or would it have had to of been some obvious external damage?

No it could not have been 'Internal' damage. It would have to have been a physical injury like a lawn mower or weed whacker or baseball bat. Maybe a cat scratching post or a beaver. Another option is freeze/sun scald damage as in a hard freeze after the sap has starting running in the spring. Did that happen and is the wound facing south?

The living cambium layer is under the bark. It is only a quarter inch thick at most, so I wouldn't call that internal. The internal is basically dead wood.

Yes it is facing due south, actually. The freezing idea makes sense, no? Since the bark still exists, but there is the larger damage underneath And the bark is falling off Around the damage.

Also if that’s what it was is there anything I should do to prevent that in the future? Sun or freeze damage?