- A favorite hike at #Haleakalā National Park is the Halemauʻu Trail to Rainbow Bridge. At 1.1 miles each way, visitors are often rewarded with a rainbow or other lovely phenomena, like Brocken Spectres. This trail offers a view into the Koʻolau Gap. NPS Photo / Regan Kelly #NationalParkWeekApr 25, 2025 20:37