Red dashed line delineates the May 24-25, 1969, fissure of the Mauna U

Red dashed line delineates the May 24-25, 1969, fissure of the Mauna Ulu eruption. Pink denotes the lava flow field produced by this episode 1 activity. Black lines show the extent of the flow field at the end of the Mauna Ulu eruption in July 1974. A dashed black line indicates sections of the original Hawai‘i Volcanoes National Park Chain of Craters Road that were covered by Mauna Ulu lava. Map source: USGS Professional Paper 1056.