Doubletree Hotel, a line of hotels trademarked by HiltonWorldwide, offers green-certified lodgings in several locations inthe United States as well as Canada and Costa Rica. A focal pointof the Think Trees from Doubletree Hotels initiative, theDoubletree Green-Certified Hotels program seeks to gaincertification and recognition for its hotels in the followingenvironmental programs: State Green Lodging Programs, Energy Star,Green Seal, Green Globe Certification, Green Key, Costa RicaCertification in Sustainable Tourism (CST), Green HotelsAssociation, and the Doubletree Environmental CARE Award.The State Green Lodging programs focus on minimizing the impactof the hotel on the environment, including reducing waste,conserving water and energy, and recycling. The criteria for theseprograms vary