US waterpark operator Great Wolf Resorts has unveiled a multi-million dollar investment to add new attractions and amenities to all 11 of its Great Wolf venues.

"We are focused on providing fun-filled experiences for the entire family in the water park and throughout the entire resort," said Tim Black, chief operating officer.

"This year our guests will find something new at each of our properties. Our goal is to create memorable vacations for guests of all ages and these brand-wide additions are great examples of how we do just that."

New amenities will include water slides, dining, shopping and interactive attractions. A white-water rafting attraction will be added to the resort in Traverse City, Michigan, as well as a bowling alley.