Rocky Mountain News: Coal-orado days are back. Almost. After a brief lull, Colorado’s coal production posted its third-best year in 2007, slightly behind the highs of 2004 but ranking No. 7 among coal-producing states in the nation. And this year promises to keep up that momentum, according to early estimates from the Colorado Geological Survey. Two new mines scheduled to go online later this year – Northfield, south of Florence, and King II in La Plata County – coupled with higher …