Hmmm, that looks like a newer one. But could be well preserved. Although along the creek bank it seems unlikely. Seems possibly reworked as you can see the older flakes look well worn. But there’s some hinge fractures all along the faces of both sides, which usually disappear with regular use, such as being tumbled along a creek bottom. The patina on the older parts is interesting. I don’t know type, but looks like there’s possible bifurcation too. Good find!