It looks like Alibates however there is also another similar looking dolomite source called Day Creek which outcrops in southwestern Kansas and in the western Oklahoma panhandle.
The quarry is on the Canadian River, not really that far from the panhandle of Oklahoma. If it was found there, it could have simply been carried. A good chunk of Oklahoma is down river from the quarry, I'm sure pieces of it have been carried down river over the last tens of thousands of years. (And probably picked up by man for a good number of those years.)
11KBP would certainly have seen more Alibates than I have, but from the couple of raw chunks I have had it isn't particularly translucent until it's heat treated. And it doesn't heat very well as thick chunks (normally it's heated as already thinned flaked blanks or spalls.) If you hold a flashlight up and it's got good translucency it might be something else.
Thank you...I believe this was found on the Ark. river, in NE okieland so how it got there...? I just think it's beautiful. and my friend who owns knows that I covet it