Can someone ID this flint type?

[archer66]

Found in a creek in Missouri. My first thought was obsidian but soon I realized that it would be unlikely in Missouri. Any ideas.

[SoIll]

Pitkin maybe..out of Arkansas.

[mirmir]

I was about ready to ask the same thing. My son found a rock that looks just about like that except that it is smaller. It is like a block and you can see where the top surface meets just like yours. Our rock was also found in a creek in Missouri.

[traderoftreasures]

i found obsidian at merimac springs st. park in mo(while trout fishing) there is a large vein there. i also found some near the gasconade river near fort.lenardwood