Question: Chouteau Island and Gateway Arch can both be found having at least half of their area in what state?

Context paragraphs:
Melaka Gateway Arch: Melaka Gateway Arch or Ayer Keroh Arch is a landmark arch to Melaka City.  It is located on Ayer Keroh Highway (Federal route ) in Ayer Keroh, Melaka, Malaysia.  It marks the Central Melaka-Alor Gajah district border.  Three towers on both sides of the arch represent the three major races in Malaysia: Malay, Chinese and Indian.

Chouteau Island: Chouteau Island ( ), situated approximately 8 mi due north of the Gateway Arch in St. Louis, Missouri, and approximately 1 mi south of the confluence of the Missouri River and Mississippi River, is one of a cluster of three islands: Chouteau Island, Gabaret Island, and Mosenthein Island.  The three, with a combined area of approximately 5500 acre , are located in Madison County, Illinois.  The three-island complex is also referred to as "Chouteau Island".  The island is manmade, having been created during the construction of the Chain of Rocks Canal between 1946 and 1953.  Most of Chouteau Island lies in Chouteau Township, but its southern quarter lies in Venice Township, both in Madison County.  Gabaret Island and Mosenthein Island both lie entirely in Venice Township.

Luther Ely Smith: Luther Ely Smith (June 11, 1873 – April 2, 1951) was a St. Louis, Missouri lawyer and civic booster.  He has been described by the National Park Service as the "father of the Jefferson National Expansion Memorial."  In the 1930s, he conceived of the idea of a memorial to President Thomas Jefferson in Saint Louis, the starting point of the Lewis and Clark Expedition and opening of the West through the city.  He chaired the Association to develop the memorial for nearly 15 years, every year but one from 1934 through 1949, after the design competition had been completed and the winner Eero Saarinen selected for his "Gateway Arch".  Construction of the Gateway Arch started in 1963, after Smith's death; it fulfilled his vision of a symbol of the city to represent its role with the American West.

Gateway Motorsports Park: Gateway Motorsports Park (formerly Gateway International Raceway) is a motorsport race track in Madison, Illinois, just east of St. Louis, Missouri, United States, close to the Gateway Arch.  It features a 1.25-mile (2 kilometer) oval used by the NASCAR Camping World Truck Series and IndyCar Series, a 1.5 mi infield road course used by SCCA and various car clubs, and quarter-mile drag strip that hosts an annual National Hot Rod Association event.

Gateway Arch: The Gateway Arch is a 630 ft monument in St. Louis in the U.S. state of Missouri.  Clad in stainless steel and built in the form of an inverted, weighted catenary arch, it is the world's tallest arch, the tallest man-made monument in the Western Hemisphere, and Missouri's tallest accessible building.  Built as a monument to the westward expansion of the United States, and officially dedicated to "the American people," it is the centerpiece of the Jefferson National Expansion Memorial and has become an internationally recognized symbol of St. Louis, as well as a popular tourist destination.

Mosenthein Island: Mosenthein Island, situated approximately 8 mi due north of the Gateway Arch in St. Louis, Missouri, and approximately 1 mi south of the confluence of the Missouri River and Mississippi River, is one of a cluster of three islands: Chouteau Island, Gabaret Island, and Mosenthein Island.  Mosenthein Island is 1,077 acres in area.  The island is mainly bottomland forest.  It is only accessible by boat.

Sunshine State Arch: Sunshine State Arch is a national historic site located at the intersection between NW.  13th Ave. and NW.  167th St. at the entrance to the Sunshine State Industrial Park, in Miami Gardens in Miami-Dade County, Florida, USA.  It was inspired by the monumental Gateway Arch in St. Louis.  The Sunshine State was finished in 1964, three years before the Gateway Arch.  It was designed by Walter C. Harry.

Malcolm W. Martin Memorial Park: Malcolm W. Martin Memorial Park is a park on the east side of the Mississippi River in East St. Louis, Illinois, directly across from the Gateway Arch and the city of St. Louis, Missouri.  Its major feature is the Gateway Geyser, a fountain that lifts water up to 630 ft .  The Gateway Geyser is a counterpart to the equally tall St. Louis monument, and is visible from the west side of the river to the right of the prominent Cargill grain elevator.  Four smaller fountains around the Geyser represent the four rivers which converge near the two cities: The Mississippi, Missouri, Illinois, and Meramec.  The park also includes an elevated viewing point overlooking the river.

St. Mary of Victories Church: The Church of St. Mary of Victories is a historic Roman Catholic church in downtown St. Louis, Missouri, in the Chouteau's Landing Historic District south of the Gateway Arch.  It was established in 1843, and was the second Catholic Church to be built in the city.  It has been listed on the National Register of Historic Places.

Gabaret Island: Gabaret Island, also known as Cabaret Island, situated approximately 8 mi due north of the Gateway Arch in St. Louis, Missouri, and approximately 1 mi south of the confluence of the Missouri River and Mississippi River, is one of a cluster of three islands: Chouteau Island, Gabaret Island, and Mosenthein Island.  Gabaret Island is 1,300 acres in area.  Due to land development, the island is continuous with its northern neighbor, Chouteau Island, but is separated by a slough (Gabaret Slough).

Supporting paragraphs: Chouteau Island Gateway Arch
Answer: Missouri