In 2007 the first model with a National Parks livery was released, the theme carried forward on other models in that year to create a small running theme. The popularity of the models was such that Mattel, Inc. decided to bring back the theme in 2018 and then continued with it for many years after. In 2021 the theme is still going strong and shows no signs of letting up. The models with this theme now form an official collection in their own right
