On May 21, 2007, Governor Jon Huntsman, Jr. announced that Utah will become the sixth state to join the Western Regional Climate Action Initiative, a joint effort to reduce regional greenhouse gas emissions and address climate change established in February 2007 by the governors of Arizona, California, New Mexico, Oregon, and Washington. The Canadian Province of British Columbia joined the initiative in April of 2007. Under the agreement, the six states and B.C. will jointly set a regional emissions target by August 2007, and by August 2008 will establish a market-based system – such as a cap-and-trade program covering multiple economic sectors – to aid in meeting the target. The participants will also set up an emissions registry and tracking system.

Press Release [1]
Map of Regional Initiatives [2]