For administrative purposes, BNSF is divided into two regions and ten operating divisions. The North Region includes the Montana, Northwest, Twin Cities, Heartland and Powder River divisions. The South Region includes the Red River, California, Chicago, Kansas and Southwest divisions. Each division is further divided into subdivisions, which represent segments of track ranging from 300-mile (482 km) mainlines to 10-mile (16 km) branch-lines. The former Texas and Gulf divisions were combined into the Red River Division, and the former Springfield and Nebraska divisions were combined into the Heartland Division, in the spring of 2016.