Business Wire -- Great Wolf Resorts, Inc.(R) (NASDAQ: WOLF), North America’s largest family of indoor waterpark resorts, today announced all its U.S. properties have achieved Green Seal(TM) certification for the lodging portion of its operations, making Great Wolf Lodge(R) brand resorts the first and only national hotel chain to earn that distinction. Green Seal is a 20-year-old, independent, non-profit organization dedicated to creating a more sustainable world. Green Seal created a rigorous, science-based environmental standard for the industry, which includes nearly three dozen environmentally responsible criteria for lodging properties.