Omaha, the most populous city in Nebraska, is located along the Missouri River and anchors an eight-county metropolitan area of about 1 million residents, with a city population of over 486,000 as of 2020. Founded in 1854 via the Lone Tree Ferry and nicknamed the Gateway to the West, it grew into a major national transportation hub, hosted the 1898 Trans-Mississippi Exposition, and later gained international prominence for its world-famous stockyards and meatpacking plants. Today, it is the corporate headquarters for four Fortune 500 companies—Berkshire Hathaway, Kiewit Corporation, Mutual of Omaha, and Union Pacific—alongside major firms like Gallup and three of the nation's top architecture and engineering outfits. Culturally, the city is renowned for the Henry Doorly Zoo and Aquarium, the Old Market, and hosting the annual College World Series, and it is the birthplace of surprising innovations such as the Reuben sandwich, the TV dinner, center-pivot irrigation, and the Top 40 radio format. The region's pioneer history stretches back to Native American tribes like the Omaha and Ponca, was explored by the Lewis and Clark Expedition in 1804, and formally opened for settlement through the 1854 treaty mediated by interpreter Logan Fontenelle.