Idaho has sent another 120 of its state prison inmates to a private prison in Colorado, bring the total transfered there in the past few months to 250. The moves are aimed at easing overpopulation in Idaho lockups; the latest group of inmates was transported by bus in four groups over the past two weeks. They're being housed at Kit Carson Correctional Center in Burlington, Colo., a medium-security prison owned and operated by Corrections Corp. of America, the same private prison firm that runs the Idaho Correctional Center south of Boise.