Final answer:
Hawaii is the state that includes both Mauna Loa and Kilauea, two of the most notable shield volcanoes with Kilauea being the most active. Mauna Kea, the tallest mountain in Hawaii and an excellent site for astronomy, is also in the state.
Step-by-step explanation:
The state with both Mauna Loa, the second highest mountain in the state and a shield volcano, and Kilauea, another shield volcano that is the most active in the region, is Hawaii. Mount Kilauea is an extremely active volcano on the island of Hawaii, which is the largest in the Hawaiian chain.
In addition to Mauna Loa and Kilauea, the island is home to Mauna Kea, Hawaii's tallest mountain at 13,796 feet above sea level, and Hualālai, a dormant volcano. Furthermore, Mauna Kea (short for Maunakea) is not only Hawaii's tallest peak but also serves as one of the premier locations for astronomy due to its dormant volcanic status.
The Hawaii hot spot is responsible for creating these volcanic features, having been active for at least 100 million years, and is part of a 3500-kilometer-long chain of volcanic islands formed by Earth's moving plates over time.