Oldman Formation

[fossil_sea_urchin]

Does the Oldman Formation reach North USA?

[jdp]

I don't think so but it is roughly equivalent to the Judith River Formation and the Two Medicine Formation.

[Troodon]

No only in Alberta.  Agreed its equivalent  to the mid section of the judith river. 

[Troodon]

Extent of Oldman Fm

[CBchiefski]

In simple terms, yes but it does not extend much into the USA, just a select part of Northern Montana. As stated, the Judith river is the best equivalent in the U.S. with the Two Med also being equivalent in time. Obviously, geologic formations do not conform to geographic boundaries. Sadly in this case there has yet to be a single paper detailing what is equivalent between the U.S. and Canada, which would be useful and I personally have desired such a paper for a while.