10/28/1990
https://www.presidency.ucsb.edu...
"It represents another step by the U.S. in discarding cold war restrictions."
"This revision is the result of a comprehensive interagency review."
"The United States hopes that all parties to these negotiations could be flexible and pragmatic in order to reach a just and lasting resolution of the problem."
"No such study of the Niobrara or the Missouri river segments has been conducted."