Omaha, Nebraska is 2 times larger than St. Louis.
Area: 342 km2 calculated
Omaha is the largest city in the state of Nebraska, United States, and is the county seat of Douglas County. It is located in the Midwestern United States on the Missouri River, about 10 miles north of the mouth of the Platte River. Wikipedia
Area: 170 km2 calculated
St. Louis is an independent city and a major United States port in eastern Missouri. The city reaches the western banks of the Mississippi River, which forms Missouri's eastern border with Illinois. At the 2010 census, St. Wikipedia