The decision now rests in President Barack Obama's hands after the court cleared an obstacle Friday that has delayed a decision following years of debate.
Premier Brad Wall says pipeline construction should proceed given the verdict as well as support for the project in the U.S. Congress.
Keystone legislation is expected to pass the House of Representatives and undergo amendments in the Senate as members stick their own priorities into the bill to increase its chances of passing.
But Obama has indicated he could veto the pipeline legislation.
Calgary-based TransCanada has been waiting more than six years for approval of the pipeline, which would carry bitumen from Alberta's oilsands to the U.S. Gulf Coast.