The Nebraska reroute of the Keystone XL was done in large part to avoid the Sand Hills, an environmentally sensitive area that encompasses parts of Wyoming, Colorado, South Dakota, Nebraska, and Kansas. This KMP Google Earth add-on map, sourced from a soil and water map by Professor Xiaodong Miao with the Illinois State Geological Survey and Prairie Research Institute at the University of Illinois at Urbana-Champaign, shows the new route well within the Sand Hills area.
For more maps, see the KMP Downloads and Links page.