Colorado is part of the RMPA (Rocky Mountain Power Area). It might not top the charts for absolute emissions. A better metric to search for would be emissions per megawatt hour (lb&#x2F;MWh).<p>In 2009, RMPA had the highest carbon emissions per megawatt hour out of the entire US, at 1,824.51 lb&#x2F;MWh [0]. It also emits nitrous oxide at a high rate, though not the highest in the country.<p>[0] <a href="http:&#x2F;&#x2F;www2.epa.gov&#x2F;sites&#x2F;production&#x2F;files&#x2F;2015-02&#x2F;documents&#x2F;egrid2012v1_0_year09_summarytables.pdf" rel="nofollow">http:&#x2F;&#x2F;www2.epa.gov&#x2F;sites&#x2F;production&#x2F;files&#x2F;2015-02&#x2F;documents...</a>