Much of the farm-raised tilpia sold in Colorado is produced by inmates at the state's prisons. It's just one of many enterprises run by Colorado Correctional Industries, or CCI.  Inmates also build furniture, make signs and even fight fires off prison grounds. The state’s prison system also has hundreds of acres where inmates raise livestock and tend crops. CCI’s director Steve Smith says CCI recently took on a new venture, after a company approached him requesting buffalo milk.  [Photo: CPR]