The concession contracts for the South Rim of the Grand Canyon are being rebid this summer, and in the first contract award Delaware North was able to snatch away some properties formerly operated by Xanterra. (Delaware North is best known for managing the concessions at Yosemite ... they operate in a number of other national parks, too, and have the former Hamilton Stores properties in Yellowstone.)
More info on the whole process at the link below, which I think illustrates some of the ridiculousness in the current NPS concession management system:
http://www.nationalparkstraveler.com/20 ... g-run25515