Interstate H-201 (H-201) is the only auxiliary Interstate Highway located outside the Contiguous United States, serving the island of O‘ahu in the U.S. state of Hawaii. The H-201 designation is also known as the Moanalua Freeway. The 4.1-mile-long (6.6 km) loop route connects exits 13 and 19 on H-1, passing Fort Shafter, Tripler Army Medical Center, and Red Hill.