The picture isn’t too sharp, but I would say this is a garter snake rather than a ribbon snake. Ribbons are slender and the scales under the jaw line (infralabial) are solid white or off-white. Garter snakes are heavier bodied and the infralabials are usually light color with dark edging. There are other scale features that differentiate the two snakes but you can’t see them in the picture.
This is a good picture. The snake looks like its ready to shed. Another difference between ribbon and garter is that the side strips of a garter run on scale rows 2 and 3. You can see that in this pic. On a ribbon they're 3 and 4.
That looks like a snake me and my dog seen in my yard. Scared us to death I don’t think either of us have run so fast in all our lives. When we went on a school field trip in 2nd grade we got to pet a ball python at the zoo. That was the only time I wasn’t scared of a snake.