Complex sentence: It was originally made part of the Hawaii National Park along with the volcanoes of Mauna Loa and Kilauea on the island of Hawaii in 1916, but was made into a separate national park in 1961.
Split into simpler sentences: It was originally created as part of the "Hawaii National Park" along with the volcanoes of Mauna Loa and Kilauea on the island of Hawaii in 1916. Hawaii Volcanoes National Park was made into a separate national park in 1961.