No, Twin Peaks is not open on Christmas. The national park is closed to visitors on December 25th to allow for the park staff and volunteers to celebrate the holiday with their families. Additionally, the park's wild areas, which are home to many unique wildlife species, require special protection and conservation measures. This includes the closure of certain areas to ensure the safety and wellbeing of the animals and visitors alike. Therefore, it is best to plan your visit to Twin Peaks on a different day when the park is open.