I assume you took that in your state of Oklahoma. It is a rat snake. There are several color variations of Pantherophis obsoletus formerly cassified as Elaphe obsoleta. The Latin name has recently been revised by taxonomist.
If you look at the various images of the rat snake it can get confusing. Here is the most common color form that I have seen. I have seen several rat snakes on the Fire Sweep Ranch not far from Oklahoma and the ones I see there are similar to the following image:
Here is one I caught last summer at Fire Sweep's Ranch.