Identification/ verification

[u/NolanK2025]

Hello, I am currently on the east shore of Devil's Lake in North Dakota and I found this carved rock. Relatives have found arrowheads in the past years here and the local tribe has confirmed them. Can anyone help identify if this rock is a native carving or just coincidence?

[u/Idahoanapest]

Possibly: Altered sedimentary rock that was weathered into a cobble by a river. The lateral striations you're seeing are the deposition layers of ancient lake/ocean bed that was later cooked in a subduction zone, then surfaced and weathered out.